Effects of the healthy start randomized intervention on psychological stress and sleep habits among obesity-susceptible healthy weight children and their parents

Nanna Julie Olsen; Sofus Christian Larsen; Jeanett Friis Rohde; Maria Stougaard; Mina Nicole Händel; Ina Olmer Specht; Berit Lilienthal Heitmann

doi:10.1371/journal.pone.0264514

. 2022 Mar 10;17(3):e0264514. doi: 10.1371/journal.pone.0264514

Effects of the healthy start randomized intervention on psychological stress and sleep habits among obesity-susceptible healthy weight children and their parents

Nanna Julie Olsen ^1,^*, Sofus Christian Larsen ¹, Jeanett Friis Rohde ¹, Maria Stougaard ², Mina Nicole Händel ¹, Ina Olmer Specht ¹, Berit Lilienthal Heitmann ^1,^3,⁴

Editor: Lee Van Horn⁵

PMCID: PMC8912262 PMID: 35271601

Abstract

Poor sleep and psychological stress are obesity determinants that are rarely included in obesity prevention programs. The aim was to report the effects of the Healthy Start randomized intervention on the secondary outcomes psychological stress and sleep duration and onset latency. Data was obtained from the Healthy Start randomized intervention conducted in 2009–2012 among Danish healthy weight children aged 2–6 years, who had either a high birth weight (>4,000 g), high maternal pre-pregnancy body mass index (>28 kg/m²), or low maternal educational level (≤10 years of schooling) and their parents. The intervention was designed to deliver improvements in diet and physical activity habits, optimization of sleep habits, and reduction of psychological family stress. The average intervention period was 15 months. Children with information on a 7-day sleep record, sleep onset latency, Strengths and Difficulties Questionnaire (SDQ), and a modified version of Parenting Stress Index (PSI) were included. The effects of the intervention on sleep habits, PSI scores, SDQ Total Difficulties (SDQ-TD) and Pro-social Behavior scores, and 95% Confidence Intervals (95% CI) were analyzed using linear regression intention-to-treat (n = 543 (intervention group n = 271, control group n = 272)) analyses. No statistically significant effects on sleep duration, sleep onset latency, PSI score, or SDQ Pro-social Behavior score were observed. Values both before and after the intervention were within the normal range both for children in the intervention and children in the control group. Mean change in SDQ-TD was 0.09 points (95% CI -0.57;0.59) in the intervention group, and -0.69 points (95% CI -1.16; -0.23) in the control group (p = 0.06). In conclusion, there were no intervention effects in relation to sleep duration, sleep onset latency, PSI score, or SDQ Pro-social behavior. There was an indication that children in the intervention group had slightly more behavioral problems than the control group after the intervention, but values were within normal range both before and after the intervention, and the difference is not considered to be clinically meaningful.

Introduction

Although children are not commonly identified as susceptible to stress, chronic exposure to stressful situations in the environment is common [1]. As chronic stress can initiate inflammatory processes in the body, which can be expressed e.g. in adipose tissue, muscle mass and hormones, stress may have adverse implications for children’s health, and may lead to an increased risk of obesity, metabolic syndrome, and cardiovascular disease [2, 3]. Information on stress in children may be obtained by measuring reactivity to stressors, for example as behavior problems. This approach is supported by previous research; in a subsample from a larger longitudinal study in the US, Hypothalamic Pituitary Axis (HPA) reactivity was measured at age 7, and internalizing symptoms via teachers reports were measured at age 5 and 11. The study found that greater HPA reactivity at age 7 was associated with greater increases in internalizing symptoms between age 5 to 11 years [4]. Similarly, a study embedded in the Dutch “Generation R” cohort found that variations in diurnal cortisol rhythm measured at age 12–20 months were associated with change in internalizing problems between 1.5 and 3 years [5].

Young children are dependent on the care of their parents, and parenting stress has been bidirectionally linked with child stress [6]. A study published in 2019, among 835 parent-child dyads, found that family conflict mediated the association between children’s behavior problems at age 1 and parenting stress at age 3, while the association between parenting stress at age 1 and behavior problems at age 3 was mediated by parental supportiveness [6]. Likewise, a recent longitudinal study found that household chaos during preschool predicted a more blunted diurnal cortisol slope in middle childhood, and that greater negative life events and greater concurrent family conflict were associated with increased free cortisol reactivity in middle childhood [7]. This suggests that efforts to reduce psychological stress in young children should focus on the entire family. Intervention tools that have been applied in previous studies to reduce psychological stress in both children and parents include increasing family time [8], resilience capacities enhancement [9], parenting training/education [10–12], and mindfulness for parents [13].

Up to 50% of parents report perceived sleep problems in toddlers, including night waking and bedtime resistance [14]. In addition to impacting daily social-emotional functioning [15], poor sleep in toddlers and primary school children can impact child growth via increased cortisol and decreased melatonin levels [16]. Because sleep problems like sleep consolidation and sleep regulation involve elements of learned behavior by definition, they are suggested to be amenable by behavioral strategies [14]. The most prevalent components in behavioral interventions targeting sleep improvements are sleep education and sleep hygiene [17]. While sleep education provides recommended sleep guidelines and emphasizes the importance of sufficient sleep in relation to health and cognition, sleep hygiene provides practices intended to support optimal sleep health [17]. In children, sleep hygiene include regular bedtime routines, an environment that supports sleep, relaxation exercises, and avoiding stimulating activities [17–19].

The aim of this study was to evaluate the effects of a multifaceted intervention on child behavioral problems, parental psychological stress, as well as on sleep duration and sleep onset latency. The intervention focused on improving diet, increasing physical activity, improving sleep duration and quality, and reducing psychological stress in the family among young children susceptible to overweight and obesity. Previously, we have reported small intervention effects on body composition (prespecified primary outcome) [20], and on diet and physical activity (secondary outcomes) [21, 22].

Methods and materials

Based on information from the Danish Medical Birth Registry (DMBR) [23], all children born in 11 municipalities in the greater Copenhagen area between 01.01.2004 and 31.12.2007 with either a high birth weight (> 4.000 g.), or a mother with overweight prior to pregnancy (BMI >28 kg/m²) (measured at the first visit at the general practitioner after becoming pregnant) were selected. Based on information from the administrative birth forms, children (n = 378) with maternal low educational level (≤ 10 years) were also selected in one municipality. In total, 5,902 children, aged 2–6 years at the time of accessing the DMBR, were selected. After selection of the study population, each child was assigned a five- or six-digit project identification number and sorted in random order. Afterwards, selected children were randomized using computer-generated randomization stratified on municipality and with simple randomization at family level. The random allocation sequence was generated by the project’s data manager. The project staff enrolled participants and assigned the children to the intervention or the control groups. They also delivered the intervention, and therefore could not be blinded regarding the group assignment of each child.

Participants were randomized into an intervention group (40%), a control group (40%), and a shadow control group (20%). Information on stress and sleep was not available in children in the shadow control group, and consequently this group will not be described further.

Children who i) moved to another municipality after birth, ii) had requested protection from participation in statistical or scientific surveys based on data delivered from the Danish Central Person Registry, iii) had no permanent address, iv) lived in a children’s home, v) had died or emigrated, or vi) were registered in the Danish Central Person Registry as being disappeared or had unknown life status, were excluded (n = 2,180).

At baseline, children in the intervention group (n = 320) had height and weight measured, and BMI was calculated. The International Obesity Task Force (IOTF) criteria for overweight (including obesity) according to age and gender from 2000 was applied [24]. Children with overweight at baseline (n = 49) were excluded, while children with healthy weight (n = 271) were included. The median number of consultations was 4 (range 2–7). The intervention period lasted on average 1.3 years (15 months). A total of 161 children completed the study.

Children in the control group (n = 315) had height and weight measured at baseline, and BMI was calculated. Children with overweight were excluded (n = 43), and children with healthy weight were included (n = 272). After on average 1.3 years, the control children and their families were invited to a follow-up examination. A total of 204 children completed the study.

Fig 1 shows a flow diagram of the Healthy Start study.

The Healthy Start intervention was conducted between May 1st, 2009 and August 31st, 2012. Trial duration was decided a priori. Deviations from the original study protocol (S1 Appendix) comprise inclusion of children from additional 6 municipalities and lowering BMI cut-off for maternal overweight prior to pregnancy from 30 kg/m² to 28 kg/m², to increase the sample size. The intervention period was shortened from the expected 2 years to 1.3 years, because the planning of practicalities related to the conduction of the study and recruitment of participants took longer than anticipated. The Healthy Start study is registered at ClinicalTrials.gov (ID NCT01583335).

The intervention

The intervention delivered guidance tailored to each of the families on how to optimize diet and increase physical activity level, as well as reduce stress in the family, and improve sleep quality and quantity of the child. Consultations took place in locations that were provided by the municipalities (e.g. schools), to ensure short transportation time for the participants.

The framework for the counselling process was based on the stages of change principles and on motivational interviewing [25, 26].

The sleep component of the intervention was focused on sleep hygiene, and recommendations for sleep duration. The stress component of the intervention was focused on spending more time as a family. The health consultants planned each consultation using developed keywords focusing on what to do to acquire/maintain healthy habits for each of the four intervention areas.

Tools to change behavior in a healthier direction were created for each keyword, to assist the consultant in providing suggestions to the family on how to do it. Examples of tools include “Provide clear rules and routines around bedtime” (sleep hygiene), or “Build up every-day routines” (stress). Together with the consultant, each family decided which tools they were motivated to work with until the next consultation, using the stages of change model [25]. To support the health consultants, and to ensure homogeneity in the delivery of the intervention, detailed descriptions on how to provide the consultations were developed by the health consultants in collaboration with the project management. The content of each session was selected from evidence-based determinants of the lifestyle habits that the Healthy Start intervention study aimed to optimize. For example, a high media consumption has been associated with a shorter sleep duration [27], and lowering media consumption could therefore increase the sleep duration. The delivery of the sessions was pilot-tested and trained internally by the health consultants and the project management. Detailed descriptions on how each session was provided have been published previously [20].

Consultations were supplemented by written information in the form of pamphlets on sleep and stress that were developed by project staff and given to the parents. The baseline session lasted for approximately one hour, while the follow-up consultation lasted for approximately one and a half hour. All sessions between baseline and follow-up lasted for approximately half an hour. The time gap between sessions was set to be maximum 4 months, corresponding to at least 3 sessions during the intervention period.

The Healthy Start intervention has been described in more details previously [20, 28].

Ethics

The Scientific Ethical Committee of the Capital Region in Denmark decided that the project was not a bioethics project, and consequently did not need approval from the Danish Bioethics Committee (journal number H-A-2007-0019). The Danish Data Protection Agency approved the study (journal number: 2015-41-3937). Written informed consent to use the collected data for research purpose was obtained from all parents.

Outcomes

Parents in both the intervention group and the control group were asked to complete a parental questionnaire at baseline and follow-up. Information about which parent (father/mother) that completed the questionnaire was not obtained. Prespecified outcome measures were child stress, parental stress, sleep duration, and sleep onset latency, which are secondary outcomes of the Healthy Start intervention.

Child behavioral problems

To indicate child psychological stress, the Danish single-sided version of the Strengths and Difficulties Questionnaire (SDQ) was included in the parental questionnaire.

The SDQ asks about 25 attributes, some positive and others negative. These 25 items are divided into 5 scales (“Emotional symptoms”, “Conduct problems”, “Hyperactivity/inattention”, “Peer relationship problems”, and “Prosocial behavior”). The scores of the “Emotional symptoms”, “Conduct problems”, “Hyperactivity/inattention”, and “Peer relationship problems” scales are summed to a SDQ-TD score, based on a scoring syntax available from the SDQ-webpage [29], and used as an exposure variable. The SDQ-TD score ranges from 0–40 points, with higher scores being worse.

The score of the “Prosocial behavior” scale (SDQ-PSB score) is not incorporated into the SDQ-TD score, as absence of prosocial behaviors differs conceptually from the presence of psychological difficulties [30]. The SDQ-PSB score ranges from 0–10 points, with higher scores being best.

The SDQ has been completed for nearly 100,000 children and adolescents in both population studies and clinical samples in the Scandinavian countries [31]. Moreover, in four large-scale Danish cohorts, SDQ has shown to be a useful screening tool for boys and girls across age groups (between 5 and 12 years) and raters (parents and teachers) [32].

Parenting stress

The Parenting Stress Index (PSI) is a self-report inventory designed to measure parental experiences of stress in the parent-child relation [33]. In order to assess the parental perceptions of the family’s well-being in terms of overall stress, 10 out of 32 questions were selected from the Swedish version and modified according to context. The questions asked which changes in life the parents had perceived since they had had the child, regarding 10 dimensions: sleep, stress, worries, time for themselves, household conflicts, work load, social gatherings in the home, joy of life, everyday surplus energy, and complexity of being a parent compared to expectations. The response options to the questions were “more”, “less”, or “no difference” compared to before having the child (e.g. “more sleep”, “less sleep”, or “no difference in sleep”). S1 Table shows the selected questions (translated from Danish into English). Each question was scored between 0 and 2 (with 0 being the best score and 2 being the worst), according to its estimated indication of an overall stress level. The PSI score ranges from 0–20, with higher scores being worse.

The Swedish version of the PSI has been validated for measuring experienced parental stress in mothers of young children [33].

Sleep habits

The parental questionnaire included a 7-day sleep record, information on duration of sleep onset latency, as well as short questions related to sleep quality. Parents were asked to record the exact times that their child fell asleep in the evening and woke up in the morning from Monday to Sunday to capture nighttime sleep duration on both weekdays and weekend days. Average nighttime sleep duration was calculated as the mean of 6 nights (i.e. Monday evening to Tuesday morning, Tuesday evening to Wednesday morning, etc.) in hours at baseline. In addition, parents were asked to report the number of minutes usually spent from the child was put to bed until sleeping (sleep onset latency).

Covariates for multiple imputations

Information on native municipality of the child, sex and age, was obtained from the DMBR [23].

In the parental questionnaire, both parents individually reported their highest educational level with nine response options, of which 8 response options were regrouped into three categories: 1) low education level (“primary and lower secondary”, “upper secondary”, “one or more short courses” and “skilled worker”), 2) medium education level (“short-term further education [<3 years]” or “medium-term further education [3–4 years]”), and 3) High education level (“long-term further education [>4 years]”, “research level”). It was not considered possible to include the ninth response option (“other”, n = 13) in any of the regrouped categories.

To indicate the children’s physical activity level, parents were asked”How physically active is the child compared to other children at the same age”. The parents could answer if they perceived their child as being “not so active”, “fairly active”, “very active” or “don’t know”.

Information on parent’s perception of their child’s sleep quality was based on the question “How do you perceive your child’s sleep?”. The response options were “the child sleeps calm through the night”, “the child sleeps a little disturbed”, “the child sleeps disturbed and wakes up once in a while”, and “the child sleeps very disturbed and wakes up several times during the night”. Parents were also asked whether the child takes naps during the day (“yes” or “no”).

Statistical methods

The sample size of the Healthy Start Study was established with the main purpose of having enough statistical power to detect a potential effect of the intervention on the primary outcome (body weight). As the present results represent a secondary study, the sample size was not determined for the purpose of these analyses. However, minimal detectible effects are calculated for all outcomes included in the present study (S2 Table), as results may not be useful without knowing if meaningful effects could be detected [34].

To test the effect of the intervention, linear regression models with treatment status included as the explanatory variable and changes in sleep duration, sleep onset latency, SDQ scores or PSI during follow-up included as the response variables were conducted. All models were adjusted for baseline measure of outcome. Model assumptions (consistency with a normal distribution and variance homogeneity) were assessed for all models through normal probability plots and residual plots.

Modified intention-to-treat analyses

Children who dropped out between baseline and follow-up were included in the analyses according to the intention-to-treat (ITT) principle using multiple imputation. In the multiple imputations, m = 10 complete data sets were generated. In each set of data, the missing values were replaced with imputed values, constructed based on predictive distributions for each of the missing values. Each of the completed data sets were analyzed, and the results from the ten analyses were combined to create a single set of estimates that comprised the variability associated with the missing values. The imputations were made using chained equations as implemented in Stata through the commands ice and mim, and based on the variables described above. Imputations were based on allocated group, municipality of birth, baseline BMI z-score, sex, age at baseline, maternal and paternal educational level, perception of the child’s sleep, if the child takes naps during the day, and physical activity compared to children in the same age. When average nighttime sleep duration was used as outcome, imputations were also made on baseline average nighttime sleep duration and SDQ-TD score. When sleep onset latency was used as outcome, imputations were also made on baseline sleep onset latency and SDQ-TD score. When SDQ-TD score was used as outcomes, imputations were also made on baseline SDQ-TD score and average nighttime sleep duration. When SDQ-PSB score was used as outcome, imputations were also made on baseline SDQ-PSB score and average nighttime sleep duration. When PSI score was used as outcome, imputations were also made on baseline PSI score.

The number of missing values ranged from 0 for the variables allocated group, municipality of birth, baseline BMI z-score, sex, and age at baseline, to 239 for paternal educational level. Distribution of observed and missing values of each variable included in the imputations are shown in S3 Table.

All statistical tests were two-sided with a significance level at 0.05. Analyses were performed using Stata SE 14 (StataCorp LP, College Station, Texas, USA; www.stata.com).

Sensitivity analyses

Per protocol analyses, removing data from children who dropped out of the intervention before the 1.3 years follow-up examination, were performed as sensitivity analyses. Per protocol analyses are shown in S4 Table. In addition, possible effect modification by sex was examined for all outcomes by adding product terms to the models. Subgroup analyses were conducted if statistically significant interactions were observed. S5 Table shows the specific outcomes stratified by completers and non-completers. Non-completers had a statistically significant higher SDQ-TD score than completers, while no other significant differences were observed.

Results

Baseline characteristics of the children included in the analyses are presented in Table 1. No differences in baseline characteristics were observed between the two groups.

Table 1. Baseline characteristics of the included participants stratified by intervention status¹.

	Intervention group		Control group
	n	Mean (SD)	n	Mean (SD)
Age (years)	271	4.02 (1.08)	272	4.02 (1.07)
Gender (% boys)	271	55.35	272	61.03
BMI Z-score (SD)	271	0.06 (0.80)	272	0.15 (0.74)
Duration of sleep (hours)	251	10.72 (0.61)	253	10.75 (0.63)
Sleep onset latency (minutes)	250	18.34 (14.51)	256	18.60 (13.85)
SDQ Total Difficulties score^a (points)	253	7.06 (3.87)	256	6.36 (3.97)
SDQ Prosocial Behavior^b (points)	253	7.67 (1.86)	256	7.81 (1.76)
Parenting Stress Index^c (points)	236	13.59 (2.76)	236	13.53 (2.34)
Sleep perception ^d	254		257
Calm (%)	153	60.24	160	62.26
A little disturbed (%)	72	28.35	74	28.79
Disturbed (%)	24	9.45	21	8.17
Very disturbed (%)	5	1.97	2	0.78
Afternoon sleep (% yes)	255	32.55	257	31.91
Physically active ^e	253		257
Not so active (%)	3	1.19	2	0.78
Fairly active (%)	92	36.36	97	37.74
Very active (%)	154	60.87	155	60.31
Don’t know (%)	4	1.58	3	1.17
Maternal education (% high level)	128	24.22	186	24.73

Open in a new tab

¹: Results presented as mean (Standard Deviation) unless otherwise stated.

^a: Range 0–40, higher scores are worse

^b: Range 0–10, higher scores are better

^c: Range 0–20, higher scores are worse

^d: Based on the question “How do you perceive your child’s sleep?”

^e: Based on the question “How physically active is the child compared to other children at the same age?”

SDQ: Strengths and Difficulties Questionnaire.

Sample size was n = 543. Sensitivity analyses showed essentially similar results as the ITT analyses presented below (S4 Table). We found no evidence of effect modification by sex for any of the outcomes (all P> 0.102).

Child behavioral problems

The mean change in SDQ-TD was 0.09 points (95% CI -0.57;0.59) in the intervention group, and -0.69 points in the control group (95% CI -1.16; -0.23) (p = 0.06) (Table 2).

Table 2. Changes in sleep and stress between baseline and follow-up (1.3 years).

		Intervention group	Control group
	n	Mean change (95% CI)	Mean change (95% CI)	P-value
Duration of sleep (hours) ^1,2	543	-0.01 (-0.11; 0.09)	0.04 (0.06; 0.08)	0.71
Onset latency (minutes) ^1, ²	543	-1.23 (-3.12; 0.66)	-2.87 (-4.56; -1.19)	0.13
SDQ Total Difficulties score (points) ¹ ^, ³	543	0.09 (-0.57; 0.59)	-0.69 (-1.16; -0.23)	0.06
SDQ Prosocial Behavior (points) ¹ ^, ³	543	0.47 (0.17; 0.76)	0.38 (0.19; 0.58)	0.61
Parenting Stress Index (points) ¹ ^, ³	543	2.27 (1.89; 2.66)	2.09 (1.72; 2.47)	0.46

Open in a new tab

SDQ: Strengths and Difficulties Questionnaire

¹: Imputations on municipality, gender, age, parental education, physical activity and baseline values of each separate outcome.

²: Imputations on parental perception of child sleep quality, taking naps during the day, baseline SDQ-TD

³: Imputations on average nighttime sleep duration at baseline.

Difference between groups tested using linear regression modeling with information on outcome, group allocation, and baseline measure of outcome. Results presented as mean changes (95% CI).

The mean change in SDQ-PSB score was 0.47 (95% CI 0.17;0.76) in the intervention group, and 0.38 (0.19;0.58) in the control group (p = 0.61) (Table 2).

Parenting stress

Mean changes in PSI score were 2.27 points (95% CI 1.89;2.66) in the intervention group, and 2.09 points (95% CI 1.72;2.47) in the control group (P = 0.46) (Table 2).

Sleep habits

Mean changes in average nighttime sleep duration were -0.01 hours (corresponding to 0.6 minutes) (95% CI -0.11;0.09) in the intervention group, and 0.04 hours (corresponding to 2.4 minutes) (95% CI 0.06;0.08) in the control group (p = 0.71) (Table 2).

Mean changes in sleep onset latency were -1.23 minutes (95% CI -3.12;0.66) in the intervention group, and -2.87 minutes (95% CI -4.56; -1.19) in the control group (p = 0.13) (Table 2).

Discussion

In this multifaceted family-based randomized intervention among healthy weight children with obesity susceptibility, we did not observe an effect of the intervention on sleep duration or sleep onset latency. Likewise, we did not observe an effect of the intervention on parenting stress. In contrast, we observed that the intervention group had a higher score as well as a larger score change in SDQ-TD, corresponding to lower socio-emotional skills or more psychological problems.

The lack of significant differences in sleep duration and sleep onset latency after the intervention may be because children in our sample had both a sleep duration and sleep onset latency within a range that can be considered as normal [35], which left little or no possibilities for improvement.

Because sleep problems may have different trajectories between infancy and middle childhood, as investigated by Williamson and colleagues [36], another possible explanation for our results could be that the follow-up period was too short to capture a prevention effect. However, the post hoc power calculations of minimal detectable effects in this study does not suggest that we have missed any clinically relevant intervention effects.

The observations of no significant differences in sleep duration and sleep onset latency after the intervention are similar to observations in previous studies; the IDEFICS study was conducted across 8 European countries (Belgium, Cyprus, Estonia, Germany, Hungary, Italy, Spain and Sweden) among 2–9 year old children, and implemented a multilevel intervention including sleep duration as a key behavioral target [37]. Although the authors observed a smaller decrease in weeknight sleep duration over the 2 years follow-up period in the intervention group compared to the control group, they concluded that the sleep component of the intervention did not lead to clinically relevant changes in sleep duration [37]. Similarly, a large cluster RCT of 3713 Chinese children introducing a school-based sleep education program on sleep duration among adolescents did not show any effects [38]. Finally, follow-up data from a parallel, 4-arm, single-blind, 2-year randomized controlled trial did not show any significant differences in nighttime sleep duration, even though results suggested that the trial arm with a brief sleep intervention in infancy reduced the risk of obesity at age 2, 3.5 and 5 years compared to the other three trial arms [39]. Considering that short sleep duration has been linked to development of obesity in children in observational studies [40], these results suggest that development of programs that are effective in improving children’s sleep habits are urgently needed.

Possible explanations for the observed non-significant differences may include the risk of type 2-error, selection bias (reflecting that the study population generally had a high socio-economic position), or attrition bias. The intervention group had a larger drop-out rate than the control group, which may have introduced a systematic drop-out that is not fully adjusted for in the multiple imputations. Even though we only observed a statistically significant difference between completers and non-completers in SDQ-TD score, this cannot be ruled out as a possible reason for failure to find effects. Another possible explanation may be that the intervention comprised multiple components rather than a single component. Even though this is a strength in terms of obesity being multifactorial, it may be hypothesized that addressing multiple lifestyle areas within a given intervention time period could reduce the intervention dose that is delivered for a specific lifestyle area, which may attenuate the exposure degree between the intervention and the control groups. Finally, the information given to all families, including those in the control group, e.g. that their child was susceptible to develop overweight and obesity, may have led to control group families having self-facilitated changes in for example physical activity level which could impact sleep habits [41]. Based on the minimal detectable effects from the power calculations for these secondary outcomes, it is considered unlikely that we have missed intervention effects that would be clinically relevant.

We did not observe any effects of the intervention on parenting stress. This implies that the intervention was not successful in reducing parenting stress (or that parents in our sample were not sufficiently stressed and that there consequently was little to intervene on), but also that participating in the intervention did not introduce additional stress to the parents. This is in line with results from a recent Canadian study that found neutral effects of their intervention on family stress level [42]. Considering that parent stress has been associated with lower physical activity and higher sedentary behaviour among the children [43], home food environment and dietary patterns [44], as well as child weight status [45], future obesity prevention interventions are still encouraged to include parent stress as a focus point in the program development. The most important limitation to our results on parenting stress is that the instrument was modified according to context and consequently was not validated, which may have increased the risk of type 2-error.

Our results suggested that children in the intervention group had increased their SDQ-TD score after the intervention period, hence had a higher degree of behavioural problems. This was surprising but may be a chance result due to multiple testing. In this regard, the SDQ-TD scores were within normal range at both baseline and follow-up, and the size of the increase in SDQ-TD score in the intervention group is not considered to be clinically significant. To the best of our knowledge, no previous obesity prevention interventions have applied SDQ as outcome measure, and it is therefore not possible to directly compare our results to previous findings. However, one previous intervention to improve emotional and behavioural self-regulation in combination with an obesity prevention program in 3–4 year old children found improved teacher-reported self-regulation, measured by a modified 60-item version of the Social Competence and Behavior Evaluation [46]. Potentially, as the intervention was multi-component, the stress component of the Healthy Start intervention was not developed or delivered sufficiently during the intervention to be effective. Another possible explanation for the observation in our study could be that participating in the intervention that focused on behaviour change have been more demanding and straining and may have affected children in the intervention group adversely in relation to stress.

Strengths of the Healthy Start study include the randomized design, which reduces the risk of potential confounding. However, the health consultants were not blinded and were therefore aware of the group allocation of the children which may have introduced a risk of observation bias. To minimize the risk of observation bias, detailed manuals and guidelines on how the consultations with both the intervention and control groups were to be conducted were developed [20].

The Healthy Start study also has limitations; the study included self-reported information that may introduce misreporting. Information on whether the sleep diary was completed by the same parent putting the child to bed in the evening and taking the child out of bed in the morning, and on which parent completed the SDQ was not obtained, which may have introduced some non-differential misclassification. Likewise, we do not have information on whether the same parent completed the PSI questionnaire at baseline and follow-up. This may have introduced some misclassification, because perceived stress may differ between mothers and fathers, as explored (for a different family stress scale), by Cooke and colleagues [47]. The consequence is an attenuation of the observed differences. In our study, child behavioral problems were used as an indicator of child psychological stress. Even though previous studies have found associations between behavioral problems and cortisol [48–52], behavioral problems could also be related to factors such as infant temperament [53] and parenting skills [54]. Another limitation to our study is hence that the extent to which SDQ-TD scores reflect stress in the child remains an open question.

Interpretation of the results may only be generalized with caution and may not be applicable to healthy weight children without obesity susceptibility. Finally, socioeconomic position may impact the willingness to participate in the Healthy Start study, which could introduce selection bias and could also reduce the generalizability of the results.

Conclusion

In this primary obesity prevention intervention, we did not see effects of the intervention in relation to sleep duration, sleep onset latency, parenting stress, or pro-social behavior. Children in the intervention group had more behavioral problems after the intervention, but the difference is not considered clinically meaningful and scores were within normal range both before and after the intervention.

Supporting information

S1 Table. Questions selected and modified from the Swedish version of the parenting stress index.

(PDF)

Click here for additional data file.^{(109KB, pdf)}

S2 Table. Minimal detectible effects for study outcomes.

(PDF)

Click here for additional data file.^{(30.1KB, pdf)}

S3 Table. Observations and numbers of missing values for imputed variables.

(PDF)

Click here for additional data file.^{(90.9KB, pdf)}

S4 Table. Changes in sleep and stress between baseline and follow-up (1.3 years).

(PDF)

Click here for additional data file.^{(32.3KB, pdf)}

S5 Table. Baseline outcomes stratified by completers and non-completers.

(PDF)

Click here for additional data file.^{(32.3KB, pdf)}

S1 Appendix. Original study protocol.

(PDF)

Click here for additional data file.^{(79.8KB, pdf)}

S2 Appendix. CONSORT checklist.

(PDF)

Click here for additional data file.^{(66KB, pdf)}

Acknowledgments

The authors would like to thank all the families participating in the Healthy Start intervention. Also, the authors would like to thank the Danish Health Visitor’s Child Health Database and the general practitioners for providing data. Finally, the authors would like to thank all the researchers, project staff, and students that helped design and conduct the Healthy Start intervention study.

Data Availability

Data from the Healthy Start intervention contains sensitive information and cannot be made publicly available for ethical and legal reasons. Public availability may compromise participant privacy, and this would not comply with Danish legislation (www.datatilsynet.dk). Access to the data requires an application submitted to and subsequently approved by the steering committee. Data requests may be sent to Professor Berit L. Heitmann (Berit.Lilienthal.Heitmann@regionh.dk) or the Research Unit for Dietary Studies at The Parker Institute (bfh-eek@regionh.dk).

Funding Statement

The Healthy Start intervention was funded by grants from the Danish Medical Research Council (grant number 271-07-0281), TrygFonden (grant number 7984-07), and the Danish Health Foundation (grant number 2008B101), all awarded to BLH. The Parker Institute at Bispebjerg and Frederiksberg Hospital was supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

References

1.Vanaelst B, Michels N, Clays E, Herrmann D, Huybrechts I, Sioen I, et al. The Association Between Childhood Stress and Body Composition, and the Role of Stress-Related Lifestyle Factors-Cross-sectional Findings from the Baseline ChiBS Survey. Int J Behav Med. 2014;21:292–301. doi: 10.1007/s12529-013-9294-1 [DOI] [PubMed] [Google Scholar]
2.Pervanidou P, Chrousos GP. Metabolic consequences of stress during childhood and adolescence. Metabolism. 2012;61(5):611–9. doi: 10.1016/j.metabol.2011.10.005 [DOI] [PubMed] [Google Scholar]
3.Murphy MO, Cohn DM, Loria AS. Developmental origins of cardiovascular disease: Impact of early life stress in humans and rodents. Neurosci Biobehav Rev. 2017;74(Pt B):453–65. doi: 10.1016/j.neubiorev.2016.07.018 [DOI] [PMC free article] [PubMed] [Google Scholar]
4.Kuhlman KR, Olson SL, Lopez-Duran NL. Predicting developmental changes in internalizing symptoms: examining the interplay between parenting and neuroendocrine stress reactivity. Dev Psychobiol. 2014;56(5):908–23. doi: 10.1002/dev.21166 [DOI] [PMC free article] [PubMed] [Google Scholar]
5.Saridjan NS, Velders FP, Jaddoe VW, Hofman A, Verhulst FC, Tiemeier H. The longitudinal association of the diurnal cortisol rhythm with internalizing and externalizing problems in pre-schoolers. The Generation R Study. Psychoneuroendocrinology. 2014;50:118–29. doi: 10.1016/j.psyneuen.2014.08.008 [DOI] [PubMed] [Google Scholar]
6.Cherry KE, Gerstein ED, Ciciolla L. Parenting stress and children’s behavior: Transactional models during Early Head Start. J Fam Psychol. 2019;33(8):916–26. doi: 10.1037/fam0000574 [DOI] [PubMed] [Google Scholar]
7.Doom JR, Cook SH, Sturza J, Kaciroti N, Gearhardt AN, Vazquez DM, et al. Family conflict, chaos, and negative life events predict cortisol activity in low-income children. Dev Psychobiol. 2018;60(4):364–79. doi: 10.1002/dev.21602 [DOI] [PMC free article] [PubMed] [Google Scholar]
8.Pigeot I, Baranowski T, De Henauw S, Group IIS, consortium I. The IDEFICS intervention trial to prevent childhood obesity: design and study methods. Obes Rev. 2015;16 Suppl 2:4–15. doi: 10.1111/obr.12345 [DOI] [PubMed] [Google Scholar]
9.Las Hayas C, Izco-Basurko I, Fullaondo A, Gabrielli S, Zwiefka A, Hjemdal O, et al. UPRIGHT, a resilience-based intervention to promote mental well-being in schools: study rationale and methodology for a European randomized controlled trial. BMC Public Health. 2019;19(1):1413. doi: 10.1186/s12889-019-7759-0 [DOI] [PMC free article] [PubMed] [Google Scholar]
10.Lachman JM, Heinrichs N, Jansen E, Bruhl A, Taut D, Fang X, et al. Preventing child mental health problems through parenting interventions in Southeastern Europe (RISE): Protocol for a multi-country cluster randomized factorial study. Contemp Clin Trials. 2019;86:105855. doi: 10.1016/j.cct.2019.105855 [DOI] [PubMed] [Google Scholar]
11.Gerards SM, Dagnelie PC, Jansen MW, van der Goot LO, de Vries NK, Sanders MR, et al. Lifestyle Triple P: a parenting intervention for childhood obesity. BMC Public Health. 2012;12:267. doi: 10.1186/1471-2458-12-267 [DOI] [PMC free article] [PubMed] [Google Scholar]
12.Hawkins KR, Apolzan JW, Staiano AE, Shanley JR, Martin CK. Efficacy of a Home-Based Parent Training-Focused Weight Management Intervention for Preschool Children: The DRIVE Randomized Controlled Pilot Trial. J Nutr Educ Behav. 2019;51(6):740–8. doi: 10.1016/j.jneb.2019.04.002 [DOI] [PMC free article] [PubMed] [Google Scholar]
13.Jastreboff AM, Chaplin TM, Finnie S, Savoye M, Stults-Kolehmainen M, Silverman WK, et al. Preventing Childhood Obesity Through a Mindfulness-Based Parent Stress Intervention: A Randomized Pilot Study. J Pediatr. 2018;202:136–42 e1. doi: 10.1016/j.jpeds.2018.07.011 [DOI] [PMC free article] [PubMed] [Google Scholar]
14.Mindell JA, Kuhn B, Lewin DS, Meltzer LJ, Sadeh A, American Academy of Sleep M. Behavioral treatment of bedtime problems and night wakings in infants and young children. Sleep. 2006;29(10):1263–76. [PubMed] [Google Scholar]
15.Hash JB, Oxford ML, Fleming CB, Ward TM, Spieker SJ. Sleep Problems, Daily Napping Behavior, and Social-Emotional Functioning among Young Children from Families Referred to Child Protective Services. Behav Sleep Med. 2020;18(4):447–59. doi: 10.1080/15402002.2019.1611579 [DOI] [PMC free article] [PubMed] [Google Scholar]
16.Copinschi G, Leproult R, Spiegel K. The important role of sleep in metabolism. Front Horm Res. 2014;42:59–72. doi: 10.1159/000358858 [DOI] [PubMed] [Google Scholar]
17.Lunsford-Avery JR, Bidopia T, Jackson L, Sloan JS. Behavioral Treatment of Insomnia and Sleep Disturbances in School-Aged Children and Adolescents. Child Adolesc Psychiatr Clin N Am. 2021;30(1):101–16. doi: 10.1016/j.chc.2020.08.006 [DOI] [PMC free article] [PubMed] [Google Scholar]
18.Hall WA, Nethery E. What does sleep hygiene have to offer children’s sleep problems? Paediatr Respir Rev. 2019;31:64–74. doi: 10.1016/j.prrv.2018.10.005 [DOI] [PubMed] [Google Scholar]
19.Wilson KE, Lumeng JC, Kaciroti N, Chen SY, LeBourgeois MK, Chervin RD, et al. Sleep Hygiene Practices and Bedtime Resistance in Low-Income Preschoolers: Does Temperament Matter? Behav Sleep Med. 2015;13(5):412–23. doi: 10.1080/15402002.2014.940104 [DOI] [PMC free article] [PubMed] [Google Scholar]
20.Olsen NJ, Angquist L, Frederiksen P, Lykke Mortensen E, Lilienthal Heitmann B. Primary prevention of fat and weight gain among obesity susceptible healthy weight preschool children. Main results from the "Healthy Start" randomized controlled intervention. Pediatr Obes. 2020:e12736. doi: 10.1111/ijpo.12736 [DOI] [PubMed] [Google Scholar]
21.Handel MN, Larsen SC, Rohde JF, Stougaard M, Olsen NJ, Heitmann BL. Effects of the Healthy Start randomized intervention trial on physical activity among normal weight preschool children predisposed to overweight and obesity. PLoS One. 2017;12(10):e0185266. doi: 10.1371/journal.pone.0185266 [DOI] [PMC free article] [PubMed] [Google Scholar]
22.Rohde JF, Larsen SC, Angquist L, Olsen NJ, Stougaard M, Mortensen EL, et al. Effects of the Healthy Start randomized intervention on dietary intake among obesity-prone normal-weight children. Public Health Nutr. 2017;20(16):2988–97. doi: 10.1017/S1368980017002026 [DOI] [PMC free article] [PubMed] [Google Scholar]
23.Bliddal M, Broe A, Pottegard A, Olsen J, Langhoff-Roos J. The Danish Medical Birth Register. Eur J Epidemiol. 2018;33(1):27–36. doi: 10.1007/s10654-018-0356-1 [DOI] [PubMed] [Google Scholar]
24.Cole TJ, Bellizzi MC, Flegal KM, Dietz WH. Establishing a standard definition for child overweight and obesity worldwide: international survey. BMJ. 2000;320(7244):1240–3. doi: 10.1136/bmj.320.7244.1240 [DOI] [PMC free article] [PubMed] [Google Scholar]
25.Prochaska JO, DiClemente CC. Stages and processes of self-change of smoking: toward an integrative model of change. J Consult Clin Psychol. 1983;51(3):390–5. doi: 10.1037//0022-006x.51.3.390 [DOI] [PubMed] [Google Scholar]
26.Rollnick S, Butler CC, Kinnersley P, Gregory J, Mash B. Motivational interviewing. BMJ. 2010;340:c1900. doi: 10.1136/bmj.c1900 [DOI] [PubMed] [Google Scholar]
27.Hitze B, Bosy-Westphal A, Bielfeldt F, Settler U, Plachta-Danielzik S, Pfeuffer M, et al. Determinants and impact of sleep duration in children and adolescents: data of the Kiel Obesity Prevention Study. Eur J Clin Nutr. 2009;63(6):739–46. doi: 10.1038/ejcn.2008.41 [DOI] [PubMed] [Google Scholar]
28.Olsen NJ, Buch-Andersen T, Handel MN, Ostergaard LM, Pedersen J, Seeger C, et al. The Healthy Start project: a randomized, controlled intervention to prevent overweight among normal weight, preschool children at high risk of future overweight. BMC Public Health. 2012;12(1):590. doi: 10.1186/1471-2458-12-590 [DOI] [PMC free article] [PubMed] [Google Scholar]
29.SDQinfo.org [Internet] [Cited 2022 Mar 3] Available from https://www.sdqinfo.org/py/sdqinfo/c0.py.
30.Goodman R. The Strengths and Difficulties Questionnaire: a research note. J Child Psychol Psychiatry. 1997;38(5):581–6. doi: 10.1111/j.1469-7610.1997.tb01545.x [DOI] [PubMed] [Google Scholar]
31.Obel C, Heiervang E, Rodriguez A, Heyerdahl S, Smedje H, Sourander A, et al. The Strengths and Difficulties Questionnaire in the Nordic countries. Eur Child Adolesc Psychiatry. 2004;13 Suppl 2:II32–II9. doi: 10.1007/s00787-004-2006-2 [DOI] [PubMed] [Google Scholar]
32.Niclasen J, Teasdale TW, Andersen AM, Skovgaard AM, Elberling H, Obel C. Psychometric properties of the Danish Strength and Difficulties Questionnaire: the SDQ assessed for more than 70,000 raters in four different cohorts. PLoS One. 2012;7(2):e32025. doi: 10.1371/journal.pone.0032025 [DOI] [PMC free article] [PubMed] [Google Scholar]
33.Ostberg M, Hagekull B, Wettergren S. A measure of parental stress in mothers with small children: dimensionality, stability and validity. Scand J Psychol. 1997;38(3):199–208. doi: 10.1111/1467-9450.00028 [DOI] [PubMed] [Google Scholar]
34.Gelman A, Carlin J. Beyond Power Calculations: Assessing Type S (Sign) and Type M (Magnitude) Errors. Perspect Psychol Sci. 2014;9(6):641–51. doi: 10.1177/1745691614551642 [DOI] [PubMed] [Google Scholar]
35.Galland BC, Short MA, Terrill P, Rigney G, Haszard JJ, Coussens S, et al. Establishing normal values for pediatric nighttime sleep measured by actigraphy: a systematic review and meta-analysis. Sleep. 2018;41(4). doi: 10.1093/sleep/zsy017 [DOI] [PubMed] [Google Scholar]
36.Williamson AA, Mindell JA, Hiscock H, Quach J. Sleep Problem Trajectories and Cumulative Socio-Ecological Risks: Birth to School-Age. J Pediatr. 2019;215:229–37 e4. doi: 10.1016/j.jpeds.2019.07.055 [DOI] [PMC free article] [PubMed] [Google Scholar]
37.Michels N, De Henauw S, Eiben G, Hadjigeorgiou C, Hense S, Hunsberger M, et al. Effect of the IDEFICS multilevel obesity prevention on children’s sleep duration. Obes Rev. 2015;16 Suppl 2:68–77. doi: 10.1111/obr.12327 [DOI] [PubMed] [Google Scholar]
38.Wing YK, Chan NY, Man Yu MW, Lam SP, Zhang J, Li SX, et al. A school-based sleep education program for adolescents: a cluster randomized trial. Pediatrics. 2015;135(3):e635–43. doi: 10.1542/peds.2014-2419 [DOI] [PubMed] [Google Scholar]
39.Taylor RW, Gray AR, Heath AM, Galland BC, Lawrence J, Sayers R, et al. Sleep, nutrition, and physical activity interventions to prevent obesity in infancy: follow-up of the Prevention of Overweight in Infancy (POI) randomized controlled trial at ages 3.5 and 5 y. Am J Clin Nutr. 2018;108(2):228–36. doi: 10.1093/ajcn/nqy090 [DOI] [PubMed] [Google Scholar]
40.Fatima Y, Doi SA, Mamun AA. Longitudinal impact of sleep on overweight and obesity in children and adolescents: a systematic review and bias-adjusted meta-analysis. Obes Rev. 2015;16(2):137–49. doi: 10.1111/obr.12245 [DOI] [PubMed] [Google Scholar]
41.Pesonen AK, Sjosten NM, Matthews KA, Heinonen K, Martikainen S, Kajantie E, et al. Temporal associations between daytime physical activity and sleep in children. PLoS One. 2011;6(8):e22958. doi: 10.1371/journal.pone.0022958 [DOI] [PMC free article] [PubMed] [Google Scholar]
42.Hruska V, Darlington G, Haines J, Ma DWL. Parent Stress as a Consideration in Childhood Obesity Prevention: Results from the Guelph Family Health Study, a Pilot Randomized Controlled Trial. Nutrients. 2020;12(6). [DOI] [PMC free article] [PubMed] [Google Scholar]
43.O’Connor SG, Maher JP, Belcher BR, Leventhal AM, Margolin G, Shonkoff ET, et al. Associations of maternal stress with children’s weight-related behaviours: a systematic literature review. Obes Rev. 2017;18(5):514–25. doi: 10.1111/obr.12522 [DOI] [PMC free article] [PubMed] [Google Scholar]
44.Jang M, Brown R, Vang PY. The Relationships Between Parental Stress, Home Food Environment, and Child Diet Patterns in Families of Preschool Children. Am J Health Promot. 2021;35(1):131–9. [DOI] [PubMed] [Google Scholar]
45.Jang M, Owen B, Lauver DR. Different types of parental stress and childhood obesity: A systematic review of observational studies. Obes Rev. 2019;20(12):1740–58. doi: 10.1111/obr.12930 [DOI] [PubMed] [Google Scholar]
46.Lumeng JC, Miller AL, Horodynski MA, Brophy-Herb HE, Contreras D, Lee H, et al. Improving Self-Regulation for Obesity Prevention in Head Start: A Randomized Controlled Trial. Pediatrics. 2017;139(5). doi: 10.1542/peds.2016-2047 [DOI] [PubMed] [Google Scholar]
47.Cooke D, Marais I, Cavanagh R, Kendall G, Priddis L. Differences Between Mothers’ and Fathers’ Ratings of Family Functioning With the Family Assessment Device. Measurement and Evaluation in Counseling and Development 2015;48(3). [Google Scholar]
48.Marsman R, Swinkels SH, Rosmalen JG, Oldehinkel AJ, Ormel J, Buitelaar JK. HPA-axis activity and externalizing behavior problems in early adolescents from the general population: the role of comorbidity and gender The TRAILS study. Psychoneuroendocrinology. 2008;33(6):789–98. doi: 10.1016/j.psyneuen.2008.03.005 [DOI] [PubMed] [Google Scholar]
49.Tyrka AR, Kelly MM, Graber JA, DeRose L, Lee JK, Warren MP, et al. Behavioral adjustment in a community sample of boys: links with basal and stress-induced salivary cortisol concentrations. Psychoneuroendocrinology. 2010;35(8):1167–77. doi: 10.1016/j.psyneuen.2010.02.002 [DOI] [PMC free article] [PubMed] [Google Scholar]
50.Ouellet-Morin I, Odgers CL, Danese A, Bowes L, Shakoor S, Papadopoulos AS, et al. Blunted cortisol responses to stress signal social and behavioral problems among maltreated/bullied 12-year-old children. Biol Psychiatry. 2011;70(11):1016–23. doi: 10.1016/j.biopsych.2011.06.017 [DOI] [PMC free article] [PubMed] [Google Scholar]
51.Hatzinger M, Brand S, Perren S, von WA, von KK, Holsboer-Trachsler E. Hypothalamic-pituitary-adrenocortical (HPA) activity in kindergarten children: importance of gender and associations with behavioral/emotional difficulties. J Psychiatr Res. 2007;41(10):861–70. doi: 10.1016/j.jpsychires.2006.07.012 [DOI] [PubMed] [Google Scholar]
52.Ruttle PL, Shirtcliff EA, Serbin LA, Fisher DB, Stack DM, Schwartzman AE. Disentangling psychobiological mechanisms underlying internalizing and externalizing behaviors in youth: longitudinal and concurrent associations with cortisol. Horm Behav. 2011;59(1):123–32. doi: 10.1016/j.yhbeh.2010.10.015 [DOI] [PMC free article] [PubMed] [Google Scholar]
53.Abulizi X, Pryor L, Michel G, Melchior M, van der Waerden J, Group EM-CCS. Temperament in infancy and behavioral and emotional problems at age 5.5: The EDEN mother-child cohort. PLoS One. 2017;12(2):e0171971. doi: 10.1371/journal.pone.0171971 [DOI] [PMC free article] [PubMed] [Google Scholar]
54.Parkes A, Green M, Mitchell K. Coparenting and parenting pathways from the couple relationship to children’s behavior problems. J Fam Psychol. 2019;33(2):215–25. doi: 10.1037/fam0000492 [DOI] [PMC free article] [PubMed] [Google Scholar]

PLoS One. doi: 10.1371/journal.pone.0264514.r001

Decision Letter 0

Lee Van Horn

21 Jun 2021

PONE-D-21-15575

Effects of the Healthy Start randomized intervention on psychological stress and sleep habits among obesity-susceptible healthy weight children and their parents.

PLOS ONE

Dear Dr. Olsen,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

First let me say that I appreciate that you are working to publish these null findings for this secondary outcome in this trial. I strongly support publishing null findings and PLOS One’s mission makes this a good fit. That said, I believe that the bar is and should be rather high for publishing null results. In particular, the current study is missing any power analyses, readers and reviewers must be convinced that the study had a good chance of finding a clinically meaningful effect if it was there. Therefore, I’m assigning a decision of major revision and asking for edits before I send the paper out for external review. Please note that if you submit a revision, the reviewer’s comments in the next round will determine the next decision. I include further discussion below of some specific comments that I noted in reading the paper.

The data analytic model is not adequately described, while you say you used regression, I don’t know if this was the outcome regressed on treatment status and controlling for baseline, or was it change in the outcome regressed on treatment status? Please document the analysis so anyone could replicate the results. Also, the language around ITT as the analysis using multiple imputation and protocol as the analysis using listwise deletion is somewhat confusing, it might be better to report just one of these (the MI results would be my preference) in the paper and then note the other one.
There appears to be substantial drop out which is greater in the treatment condition than the control condition. I would find this concerning in any intervention, while MI may partially adjust for this it wouldn’t adjust for systematic dropout (some families were unhappy with the treatment, or the children were doing well and so they didn’t want any more contact). This should be explored somewhat more and mentioned as a possible reason for failure to find effects.
I’m doing this review off-line and so I don’t have access to the clinical trials registration, but I will read it for the next round and would hope that initial protocols were followed and any deviations explained.
Power analyses are required and to the extent that these were originally done for these outcomes, the original power analyses should be presented. If they were not done for these outcomes then new power analyses are needed, paying particular attention to justifying the effect size that is hypothesized for each of the outcomes given other intervention studies, clinically meaningful effects, and noting the reliability of the outcome measures (measures with low reliability would generally have smaller effect sizes). There should be enough detail in the power analyses that I could replicate the results.

Please submit your revised manuscript by Jul 23 2021 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Lee Van Horn, PhD

Academic Editor

PLOS ONE

Journal Requirements:

When submitting your revision, we need you to address these additional requirements.

1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at

https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and

https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf

2. Please include captions for your Supporting Information files Protocol and CONSORT checklist at the end of your manuscript, and update any in-text citations to match accordingly. Please see our Supporting Information guidelines for more information: http://journals.plos.org/plosone/s/supporting-information.

3.We note that you have indicated that data from this study are available upon request. PLOS only allows data to be available upon request if there are legal or ethical restrictions on sharing data publicly. For information on unacceptable data access restrictions, please see http://journals.plos.org/plosone/s/data-availability#loc-unacceptable-data-access-restrictions.

In your revised cover letter, please address the following prompts:

a) If there are ethical or legal restrictions on sharing a de-identified data set, please explain them in detail (e.g., data contain potentially identifying or sensitive patient information) and who has imposed them (e.g., an ethics committee). Please also provide contact information for a data access committee, ethics committee, or other institutional body to which data requests may be sent.

b) If there are no restrictions, please upload the minimal anonymized data set necessary to replicate your study findings as either Supporting Information files or to a stable, public repository and provide us with the relevant URLs, DOIs, or accession numbers. Please see http://www.bmj.com/content/340/bmj.c181.long for guidelines on how to de-identify and prepare clinical data for publication. For a list of acceptable repositories, please see http://journals.plos.org/plosone/s/data-availability#loc-recommended-repositories.

We will update your Data Availability statement on your behalf to reflect the information you provide.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

PLoS One. 2022 Mar 10;17(3):e0264514. doi: 10.1371/journal.pone.0264514.r002

Author response to Decision Letter 0

27 Aug 2021

Frederiksberg, August 25th, 2021

Manuscript ID PONE-D-21-15575

Dear Editor

Thank you for the comments to our manuscript. The comments are included below and our response to each point is marked in italic. In addition to the comments, we have added some minor typographical and linguistic improvements added to the paper.

All changes in the revised paper are marked with tracked changes. A clean revision with no tracked changes is also uploaded. Please note that the page- and line numbers below are based on the clean revision.

We very much appreciate constructive comments and suggestions.

Editor Comments to Author:

1. The data analytic model is not adequately described, while you say you used regression, I don’t know if this was the outcome regressed on treatment status and controlling for baseline, or was it change in the outcome regressed on treatment status? Please document the analysis so anyone could replicate the results. Also, the language around ITT as the analysis using multiple imputation and protocol as the analysis using listwise deletion is somewhat confusing, it might be better to report just one of these (the MI results would be my preference) in the paper and then note the other one.

The analyses were performed using change in the outcome regressed on treatment status. Based on the comment, the Statistical methods section has been rewritten with the aim of improving the description of the data analytical model.

Page 11, line 252: “To test the effect of the intervention, linear regression models with treatment status included as the explanatory variable and changes in sleep duration, sleep onset latency, SDQ scores or PSI during follow-up included as the response variables were conducted. All models were adjusted for baseline measure of outcome.”

Table 2, headline: “Changes in sleep and stress between baseline and follow-up (1.3 years).”

Page 11, line 258: “Children who dropped out between baseline and follow-up were included in the analyses according to the intention-to-treat (ITT) principle using multiple imputation. In the multiple imputations, m=10 complete data sets were generated. In each set of data, the missing values were replaced with imputed values, constructed based on predictive distributions for each of the missing values. Each of the completed data sets were analyzed, and the results from the ten analyses were combined to create a single set of estimates that comprised the variability associated with the missing values. The imputations were made using chained equations as implemented in Stata through the commands ice and mim, and based on the variables described above. Imputations were based on allocated group, municipality of birth, baseline BMI z-score, sex, age at baseline, maternal and paternal educational level, perception of the child’s sleep, if the child takes naps during the day, and physical activity compared to children in the same age. When average nighttime sleep duration was used as outcome, imputations were also made on baseline average nighttime sleep duration and SDQ-TD score. When sleep onset latency was used as outcome, imputations were also made on baseline sleep onset latency and SDQ-TD score. When SDQ-TD score was used as outcomes, imputations were also made on baseline SDQ-TD score and average nighttime sleep duration. When SDQ-PSB score was used as outcome, imputations were also made on baseline SDQ-PSB score and average nighttime sleep duration. When PSI score was used as outcome, imputations were also made on baseline PSI score. All statistical tests were two-sided with a significance level at 0.05. Analyses were performed using Stata SE 14 (StataCorp LP, College Station, Texas, USA; www.stata.com).”

Page 12, line 280: “Per protocol analyses, removing data from children who dropped out of the intervention before the 1.3 years follow-up examination, were performed as sensitivity analyses. Per protocol analyses are shown in Supporting S3 table. In addition, possible effect modification by sex was examined in all models.”

Thank you for the suggestion to report just one of the analyses. We have revised the manuscript and now present only the MI results and have moved the protocol analyses to Supporting S3 table. We have rephrased the results sections accordingly and have deleted any text on the protocol analyses (pages 14-16). We have also removed the results from the protocol analyses from Table 2.

In addition, we have rephrased the abstract and the manuscript text:

Abstract, line 46: “…. and 95% Confidence Intervals (95% CI) were analyzed using linear regression intention-to-treat (n=543 (intervention group n=271, control group n=272)) analyses.”

Abstract, line 51: “Mean change in SDQ-TD was 0.09 points (95% CI -0.57;0.59) in the intervention group, and -0.69 points (95% CI -1.16; -0.23) in the control group (p=0.06).”

Page 12, line 290: “Sample size was n=543”

2. There appears to be substantial drop out which is greater in the treatment condition than the control condition. I would find this concerning in any intervention, while MI may partially adjust for this it wouldn’t adjust for systematic dropout (some families were unhappy with the treatment, or the children were doing well and so they didn’t want any more contact). This should be explored somewhat more and mentioned as a possible reason for failure to find effects.

We have added a table to the manuscript with outcomes stratified by completers and non-completers, showing that non-completers had a statistically significant higher SDQ-TD score than completers, while no other significant differences were observed.

Page 12, line 283: “Supporting S4 table shows the specific outcomes stratified by completers and non-completers. Non-completers had a statistically significant higher SDQ-TD score than completers, while no other significant differences were observed.”

This has also been addressed in the Discussion section:

Page 17, line 340: “The intervention group had a larger drop-out rate than the control group, which may have introduced a systematic drop-out that is not fully adjusted for in the multiple imputations. Even though we only observed a statistically significant difference between completers and non-completers in SDQ-TD score, this cannot be ruled out as a possible reason for failure to find effects.”

3. I’m doing this review off-line and so I don’t have access to the clinical trials registration, but I will read it for the next round and would hope that initial protocols were followed and any deviations explained.

Page 6, line 139: “The intervention period was shortened from the expected 2 years to 1.3 years, because the planning of practicalities related to the conduction of the study and recruitment of participants took longer than anticipated.”

The original protocol has been uploaded as Supporting S1 Appendix.

4. Power analyses are required and to the extent that these were originally done for these outcomes, the original power analyses should be presented. If they were not done for these outcomes then new power analyses are needed, paying particular attention to justifying the effect size that is hypothesized for each of the outcomes given other intervention studies, clinically meaningful effects, and noting the reliability of the outcome measures (measures with low reliability would generally have smaller effect sizes). There should be enough detail in the power analyses that I could replicate the results.

Page 10, line 247: “The sample size of the Healthy Start Study was established with the main purpose of having enough statistical power to detect a potential effect of the intervention on the primary outcome (body weight). As the present results represent a secondary study, the sample size was not determined for the purpose of these analyses. However, minimal detectible effects are calculated for all outcomes included in the present study (Supporting S2 table).”

Page 17, line 352: “Based on the minimal detectable effects from the power calculations for these secondary outcomes, it is considered unlikely that we have missed intervention effects that would be clinically relevant.“

Attachment

Submitted filename: Response_EditorComments.docx

Click here for additional data file.^{(19.3KB, docx)}

PLoS One. doi: 10.1371/journal.pone.0264514.r003

Decision Letter 1

Lee Van Horn

22 Nov 2021

PONE-D-21-15575R1Effects of the Healthy Start randomized intervention on psychological stress and sleep habits among obesity-susceptible healthy weight children and their parents.

PLOS ONE

Dear Dr. Olsen,

I now have reviews for your paper from 4 reviewers, 3 of whom had significant comments. Based on the consensus of these reviewers and my own reading of your paper my editorial decision is that a minor revision is still needed before the paper could be published in Plos ONE. Please pay attention to all of the comments, that said, I disagree with reviewer 1 who says that the analyses on detectable differences are not needed since this is a secondary analysis. While there is some controversy over use of post hoc methods for power, the controversy stems from other issues rather than the issue here where you did not find the effect and are making the case for there being no meaningful effect given the study design. I wouldn’t be willing to accept a paper with null findings without a measure of power, without knowing if you could have found a meaningful effect the results are not very useful. A good reference for this is:

Gelman, A., and Carlin, J. B. (2014). Beyond power calculations: Assessing Type S (sign) and Type M (magnitude) errors. Perspectives on Psychological Science 9, 641-651.

Review 3 notes that it might have been odd to expect an effect on sleep given that most of your subjects were in the normal range to begin with. I think a response to this and inclusion of the power analyses might go hand in hand.

Please submit your revised manuscript by Jan 06 2022 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Lee Van Horn, PhD

Academic Editor

PLOS ONE

Journal Requirements:

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

Additional Editor Comments (if provided):

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: (No Response)

Reviewer #2: (No Response)

Reviewer #3: (No Response)

Reviewer #4: (No Response)

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Partly

Reviewer #4: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: I Don't Know

Reviewer #4: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: No

Reviewer #3: Yes

Reviewer #4: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Since this is the secondary analysis, it is not meaningful to calculate the detectable effect size based on the collected sample size. Remove the sentence of Line 250-251 and table S2. You can add the reference to the power for the main study in Line 247-249.

Table 1. Since Wilcoxon was used, better present median with IQR.

Table 2 footnote, add covariates adjusted in the regression model. Did you test normality of the regression, however, nonparametric method was used in Table 1. This needs justification.

Flowchart better use two arms for intervention and control groups.

You can briefly mention the findings from the sensitivity analysis in the Results section.

Reviewer #2: Dear authors and editorial team,

Thank you for the opportunity to review this manuscript. I declare that I do not have any competing interests in completing this role. The aim of this study was to investigate changes to children’s sleep quality and parents’ and children’s perceived stress as secondary outcomes of a family-based obesity prevention randomized controlled trail. The authors report no statistically significant differences at follow-up, but nevertheless, this research adds to our collective understanding of the many factors that shape children’s obesity and chronic disease risk. The manuscript is well-written and the analyses are thorough. I have provided minor suggestions to improve clarity. Thank you for continuing this important work into protecting families’ long-term health and happiness.

Introduction, page 3, lines 62-70: The first sentence provides a good opening, but the remainder of the paragraph seems somewhat abrupt. Your abstract introduction presents the link between children's stress and chronic illness risk upfront, and I would recommend adding a similar sentence or two to this beginning paragraph to underscore the relevance of chronic stress to children's health, then continue with the description of stress assessment strategies. E.g., "... chronic exposure to environmental stressors is common. This has adverse implications for children's health because chronic stress is associated with obesity risk, poor sleep, etc.". Additionally, no capitalization is required after the semicolon in line 64 (“In” to “in”).

Introduction, page 3, line 79: “suggest” should be “suggests”.

Child stress methods, page 8, line 196: I believe you meant “100,000 children” with a comma instead of a period.

Child stress methods, page 9, line 215: capitalize “Swedish”.

Modified intention-to-treat analyses, page 11, lines 268-275: It would be helpful to the reader to contextualize the missing data if the numbers of participants with imputed values were described. This could be added in line where each variable is described, e.g. “Where PSI score was used as an outcome, imputations were also made on baseline PSI score for n = X participants”.

Sensitivity analyses, page 12, line 282: What is meant by “possible effect modification by sex”? Was this tested as moderation with interaction terms, in mediation path analyses, or another method you could describe further?

Discussion, page 19, lines 388-389: I agree that multi-parent responses to the SDQ may have complicated the data. I also wonder if this applies to the PSI results. You mention earlier in the paper that gender of the reporting parent was not assessed, but is it possible to know if the same parent completed both baseline and follow-up PSI surveys? Perceived stress is a highly subjective and gendered concept, and so potential differences between family members or gender differences in stress perception may have also contributed to the observed results. Cooke and colleagues explore this in their paper, albeit for a different family stress scale (DOI: 10.1177/0748175615578756).

Figure 1: Small formatting adjustment needed to read all content in box with “Randomized to allocation group followed in national registers”.

Reviewer #3: Below are my comments:

BACKGROUND/HYPOTHESIS

1. While the references (2&3) supports the level of cortisol reactivity to stress in children predicts internalizing problem in a later age, which illustrates an association between cortisol level and behavioral problem. Nonetheless, behavioral problem in children could be related to a wide range of factors such as parenting skills and child temperament. It does not seem appropriate to assume SDQ is a measurement of child stress. Rather, the authors could make it explicit that this manuscript focuses on the behavioral problems of the participants.

2. As commented by the authors, the baseline sleep duration and SDQ are within normal range, what would be the intended intervention effects that the authors would like to see? Would there be a subgroup of participants who had subthreshold sleep and stress problem that could benefit more from the intervention?

METHOD

1. From the original protocol attached as Appendix 1, the intervention described focused on nutritional counselling and physical activity. Whereas in the introduction, line 97, authors reports that the intervention “focused on improving diet, increasing physical activity, improving sleep duration and quality and reducing psychological stress in the family…”. In that case, the authors would have to elaborate on what intervention was being offered to improve the sleep and psychological stress of the family, so as to allow replication by others.

2. Line 193: for clarity, the authors should explained what consists of the SDQ-TD and SDQ-PSB score.

3. Line 198: for clarity, the authors should state what condition have been validated to use SDQ as a screening tool.

RESULTS

1. Table 1 showed the baseline characteristics of the participants and this should include all participants as illustrate in the flowchart (N=543). In the current version, Table 1 reports only the results of 307 participants, does it mean that data of the remaining 236 participants were already missing at the baseline? In that case, what data were used to compose Suppl Table 4: Baseline outcomes of completers (N=303) and non-completers (N=201)?

DISCUSSION

As the participants in this study has normal sleep and stress parameters to begin with, the intervention from this study is also preventive by nature. The authors may discuss about the trajectory/ emergence on the sleep in child (Williamson A et al J Pediatr 2019), and that this study may not have a long enough follow up to capture the prevention effect. Likewise, the authors may analyze a subgroup of high-risk case with subthreshold sleep problem and see if the intervention effects could be seen.

Reviewer #4: (No Response)

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: Yes: Valerie Hruska

Reviewer #3: No

Reviewer #4: No

PLoS One. 2022 Mar 10;17(3):e0264514. doi: 10.1371/journal.pone.0264514.r004

Author response to Decision Letter 1

20 Jan 2022

Frederiksberg, January 20th, 2022

Manuscript ID PONE-D-21-15575R1

Dear Editor

On behalf of all authors, I would like to sincerely thank you and the reviewers for the very thorough and constructive review of our manuscript.

The comments are included below, and our response to each point is marked in italic. In addition to the comments, we have added some minor typographical and linguistic improvements to the paper.

We very much appreciate the constructive comments and suggestions that we have received.

Editor comments

Gelman, A., and Carlin, J. B. (2014). Beyond power calculations: Assessing Type S (sign) and Type M (magnitude) errors. Perspectives on Psychological Science 9, 641-651.

Thank you very much for the very comprehensive and constructive evaluation of our manuscript. It is greatly appreciated.

Journal Requirements

We have scrutinized the reference list and have not identified any articles that have been retracted.

We have made the following changes to the reference list:

Reference 1 has been corrected (publication date updated)

Reference 14 has been corrected (author list updated (American Academy of Sleep Medicine has been spelled out))

Reference 31 in Revision 1 (Knudsen LB, Olsen J. The Danish Medical Birth Registry. Dan Med Bull. 1998;45(3):320-3.) has been replaced with reference 23 in Revision 2 (Bliddal M, Broe A, Pottegard A, Olsen J, Langhoff-Roos J. The Danish Medical Birth Register. Eur J Epidemiol. 2018;33(1):27-36.), as this reference is more new.

New references have been added according to editor and reviewer comments (reference numbers 2, 3, 27, 34, 36, 47-54)

Additional Editor Comments (if provided):

________________________________________

Review Comments to the Author

Reviewer #1

Since this is the secondary analysis, it is not meaningful to calculate the detectable effect size based on the collected sample size. Remove the sentence of Line 250-251 and table S2. You can add the reference to the power for the main study in Line 247-249.

We respectfully disagree with this comment, as the results may not be very useful without knowing if meaningful effects could have been detected.

Line 260-261: “…, as results may not be useful without knowing if meaningful effects could be detected”

Table 1. Since Wilcoxon was used, better present median with IQR.

Thank you for bringing this to our attention. We did not test for differences in baseline characteristics because of the randomized design. The footnote on using Wilcoxon and Chi-squared tests has therefore been deleted.

Table 2 footnote, add covariates adjusted in the regression model.

Table 2 footnote: “Difference between groups tested using linear regression modeling with information on outcome, group allocation, and baseline measure of outcome.”

Did you test normality of the regression, however, nonparametric method was used in Table 1. This needs justification.

As described above, the footnote on nonparametric tests has been deleted from Table 1.

Model assumptions were assessed for all models through normal probability plots and residual plots. This has been specified:

Lines 265-266: “Model assumptions (consistency with a normal distribution and variance homogeneity) were assessed for all models through normal probability plots and residual plots.”

Flowchart better use two arms for intervention and control groups.

The flowchart has been updated, using two arms for intervention and control groups

You can briefly mention the findings from the sensitivity analysis in the Results section.

Thank you for this great suggestion. We have added the following sentence in the results section:

Lines 309-310: “Sensitivity analyses showed essentially similar results as the ITT analyses presented below (Supporting S4 table). “

Reviewer #2

Dear authors and editorial team,

Thank you for the kind words on our work.

Thank you for this suggestion. We have added the following sentence to the introduction:

Lines 60-63: “As chronic stress can initiate inflammatory processes in the body, which can be expressed e.g. in adipose tissue, muscle mass and hormones, stress may have adverse implications for children’s health, and may lead to an increased risk of obesity, metabolic syndrome, and cardiovascular disease”

Additionally, no capitalization is required after the semicolon in line 64 (“In” to “in”).

Corrected

Introduction, page 3, line 79: “suggest” should be “suggests”.

Corrected

Child stress methods, page 8, line 196: I believe you meant “100,000 children” with a comma instead of a period.

Corrected

Child stress methods, page 9, line 215: capitalize “Swedish”.

Corrected

Thank you for this suggestion. We have added this information to the manuscript and have made a new Supplemental S3 table.

Lines 289-292: “The number of missing values ranged from 0 for the variables allocated group, municipality of birth, baseline BMI z-score, sex, and age at baseline, to 239 for paternal educational level. Distribution of observed and missing values of each variable included in the imputations are shown in Supporting S3 table.”

This has now been specified:

Lines 300-302: “In addition, possible effect modification by sex was examined for all outcomes by adding product terms to the models. Subgroup analyses were conducted if statistically significant interactions were observed.”

Lines 310-311: “We found no evidence of effect modification by sex for any of the outcomes (all P> 0.102).”

Thank you for making this excellent point. We do not have information on whether the PSI surveys were completed by the same parent at baseline and follow-up. We have added this as a limitation in the discussion section:

Lines 415-419: “Likewise, we do not have information on whether the same parent completed the PSI questionnaire at baseline and follow-up. This may have introduced some misclassification, because perceived stress may differ between mothers and fathers, as explored (for a different family stress scale), by Cooke and colleagues. The consequence is an attenuation of the observed differences.”

Figure 1: Small formatting adjustment needed to read all content in box with “Randomized to allocation group followed in national registers”.

Thank you for bringing this to our attention. Figure 1 has been updated, including the box of the shadow control group.

Reviewer #3

Below are my comments:

BACKGROUND/HYPOTHESIS

Thank you for this constructive comment. We have added the point that behavioral problems may not reflect stress as a limitation in the discussion section:

Lines 419-423: “In our study, child behavioral problems were used as an indicator of child psychological stress. Even though previous studies have found associations between behavioral problems and cortisol, behavioral problems could also be related to factors such as infant temperament and parenting skills. Another limitation to our study is hence that the extent to which SDQ-TD scores reflect stress in the child remains an open question.”

To make it explicit that this manuscript focuses on child behavioral problems, we have made the following adjustments:

Lines 95-96: “The aim of this study was to evaluate the effects of a multifaceted intervention on child behavioral problems, parental psychological stress, as well as on sleep duration and sleep onset latency.”

Line 193: Headline has been changed to “Child behavioral problems”

Line 316: Headline has been changed to “Child behavioral problems”

Lines 194-195: “To indicate child psychological stress, the Danish single-sided version of the Strengths and Difficulties Questionnaire was included in the parental questionnaire.”

Thank you for this excellent question. Considering that the primary aim of the intervention was to prevent overweight development, and that short sleep duration and a high level of stress are considered risk factors for overweight development, the intended intervention effects that we would have liked to see are a longer sleep duration in the intervention group compared to the control group, and a lower SDQ score in the intervention group compared to the control group. It could certainly be hypothesized that there would be a subgroup of participants who had subthreshold sleep and stress problems, where any larger intervention effects may have been diluted. Unfortunately, we do not believe our sample has sufficient statistical power to conduct such analyses.

METHOD

Lines 153-155: “The sleep component of the intervention was focused on sleep hygiene, and recommendations for sleep duration. The stress component of the intervention was focused on spending more time as a family.”

Lines 161-170: “To support the health consultants, and to ensure homogeneity in the delivery of the intervention, detailed descriptions on how to provide the consultations were developed by the health consultants in collaboration with the project management. The content of each session was selected from evidence-based determinants of the lifestyle habits that the Healthy Start intervention study aimed to optimize. For example, a high media consumption has been associated with a shorter sleep duration, and lowering media consumption could therefore increase the sleep duration. The delivery of the sessions was pilot-tested and trained internally by the health consultants and the project management. Detailed descriptions on how each session was provided have been published previously.”

2. Line 193: for clarity, the authors should explained what consists of the SDQ-TD and SDQ-PSB score.

Lines 198-202: “The scores of the “Emotional symptoms”, “Conduct problems”, “Hyperactivity/inattention”, and “Peer relationship problems” scales are summed to a SDQ-TD score, based on a scoring syntax available from the SDQ-webpage, and used as an exposure variable. The SDQ-TD score ranges from 0-40 points, with higher scores being worse.

Lines 203-205: “The score of the “Prosocial behavior” scale (SDQ-PSB score) is not incorporated into the SDQ-TD score, as absence of prosocial behaviors differs conceptually from the presence of psychological difficulties”

3. Line 198: for clarity, the authors should state what condition have been validated to use SDQ as a screening tool.

This paragraph has been rewritten:

Lines 206-209: “The SDQ has been completed for nearly 100,000 children and adolescents in both

population studies and clinical samples in the Scandinavian countries. Moreover, in four large-scale Danish cohorts, SDQ has shown to be a useful screening tool for boys and girls across age groups (between 5 and 12 years) and raters (parents and teachers)”

RESULTS

Thank you for bringing this to our attention. We have updated Table 1 so it now includes all participants as illustrated in the flowchart (n=543)

DISCUSSION

Thank you for this excellent point. We have added to the discussion section:

Lines 342-346: “Because sleep problems may have different trajectories between infancy and middle childhood, as investigated by Williamson and colleagues, another possible explanation for our results could be that the follow-up period was too short to capture a prevention effect. However, the post hoc power calculations of minimal detectable effects in this study does not suggest that we have missed any clinically relevant intervention effects.”

Reviewer #4

(No Response)

________________________________________

Attachment

Submitted filename: ResponseReviewers_Revision2.docx

Click here for additional data file.^{(34.6KB, docx)}

PLoS One. doi: 10.1371/journal.pone.0264514.r005

Decision Letter 2

Lee Van Horn

14 Feb 2022

Effects of the Healthy Start randomized intervention on psychological stress and sleep habits among obesity-susceptible healthy weight children and their parents.

PONE-D-21-15575R2

Dear Dr. Olsen,

Thank you for your work in addressing the concerns raised by the reviewers and myself. After carefully reading the manuscript I'm pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.

If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

Lee Van Horn, PhD

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

PLoS One. doi: 10.1371/journal.pone.0264514.r006

Acceptance letter

Lee Van Horn

28 Feb 2022

PONE-D-21-15575R2

Effects of the Healthy Start randomized intervention on psychological stress and sleep habits among obesity-susceptible healthy weight children and their parents.

Dear Dr. Olsen:

I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org.

If we can help with anything else, please email us at plosone@plos.org.

Thank you for submitting your work to PLOS ONE and supporting open access.

Kind regards,

PLOS ONE Editorial Office Staff

on behalf of

Dr. Lee Van Horn

Academic Editor

PLOS ONE

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

S1 Table. Questions selected and modified from the Swedish version of the parenting stress index.

(PDF)

Click here for additional data file.^{(109KB, pdf)}

S2 Table. Minimal detectible effects for study outcomes.

(PDF)

Click here for additional data file.^{(30.1KB, pdf)}

S3 Table. Observations and numbers of missing values for imputed variables.

(PDF)

Click here for additional data file.^{(90.9KB, pdf)}

S4 Table. Changes in sleep and stress between baseline and follow-up (1.3 years).

(PDF)

Click here for additional data file.^{(32.3KB, pdf)}

S5 Table. Baseline outcomes stratified by completers and non-completers.

(PDF)

Click here for additional data file.^{(32.3KB, pdf)}

S1 Appendix. Original study protocol.

(PDF)

Click here for additional data file.^{(79.8KB, pdf)}

S2 Appendix. CONSORT checklist.

(PDF)

Click here for additional data file.^{(66KB, pdf)}

Attachment

Submitted filename: Response_EditorComments.docx

Click here for additional data file.^{(19.3KB, docx)}

Attachment

Submitted filename: ResponseReviewers_Revision2.docx

Click here for additional data file.^{(34.6KB, docx)}

Data Availability Statement

[pone.0264514.ref001] 1.Vanaelst B, Michels N, Clays E, Herrmann D, Huybrechts I, Sioen I, et al. The Association Between Childhood Stress and Body Composition, and the Role of Stress-Related Lifestyle Factors-Cross-sectional Findings from the Baseline ChiBS Survey. Int J Behav Med. 2014;21:292–301. doi: 10.1007/s12529-013-9294-1 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref002] 2.Pervanidou P, Chrousos GP. Metabolic consequences of stress during childhood and adolescence. Metabolism. 2012;61(5):611–9. doi: 10.1016/j.metabol.2011.10.005 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref003] 3.Murphy MO, Cohn DM, Loria AS. Developmental origins of cardiovascular disease: Impact of early life stress in humans and rodents. Neurosci Biobehav Rev. 2017;74(Pt B):453–65. doi: 10.1016/j.neubiorev.2016.07.018 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref004] 4.Kuhlman KR, Olson SL, Lopez-Duran NL. Predicting developmental changes in internalizing symptoms: examining the interplay between parenting and neuroendocrine stress reactivity. Dev Psychobiol. 2014;56(5):908–23. doi: 10.1002/dev.21166 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref005] 5.Saridjan NS, Velders FP, Jaddoe VW, Hofman A, Verhulst FC, Tiemeier H. The longitudinal association of the diurnal cortisol rhythm with internalizing and externalizing problems in pre-schoolers. The Generation R Study. Psychoneuroendocrinology. 2014;50:118–29. doi: 10.1016/j.psyneuen.2014.08.008 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref006] 6.Cherry KE, Gerstein ED, Ciciolla L. Parenting stress and children’s behavior: Transactional models during Early Head Start. J Fam Psychol. 2019;33(8):916–26. doi: 10.1037/fam0000574 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref007] 7.Doom JR, Cook SH, Sturza J, Kaciroti N, Gearhardt AN, Vazquez DM, et al. Family conflict, chaos, and negative life events predict cortisol activity in low-income children. Dev Psychobiol. 2018;60(4):364–79. doi: 10.1002/dev.21602 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref008] 8.Pigeot I, Baranowski T, De Henauw S, Group IIS, consortium I. The IDEFICS intervention trial to prevent childhood obesity: design and study methods. Obes Rev. 2015;16 Suppl 2:4–15. doi: 10.1111/obr.12345 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref009] 9.Las Hayas C, Izco-Basurko I, Fullaondo A, Gabrielli S, Zwiefka A, Hjemdal O, et al. UPRIGHT, a resilience-based intervention to promote mental well-being in schools: study rationale and methodology for a European randomized controlled trial. BMC Public Health. 2019;19(1):1413. doi: 10.1186/s12889-019-7759-0 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref010] 10.Lachman JM, Heinrichs N, Jansen E, Bruhl A, Taut D, Fang X, et al. Preventing child mental health problems through parenting interventions in Southeastern Europe (RISE): Protocol for a multi-country cluster randomized factorial study. Contemp Clin Trials. 2019;86:105855. doi: 10.1016/j.cct.2019.105855 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref011] 11.Gerards SM, Dagnelie PC, Jansen MW, van der Goot LO, de Vries NK, Sanders MR, et al. Lifestyle Triple P: a parenting intervention for childhood obesity. BMC Public Health. 2012;12:267. doi: 10.1186/1471-2458-12-267 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref012] 12.Hawkins KR, Apolzan JW, Staiano AE, Shanley JR, Martin CK. Efficacy of a Home-Based Parent Training-Focused Weight Management Intervention for Preschool Children: The DRIVE Randomized Controlled Pilot Trial. J Nutr Educ Behav. 2019;51(6):740–8. doi: 10.1016/j.jneb.2019.04.002 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref013] 13.Jastreboff AM, Chaplin TM, Finnie S, Savoye M, Stults-Kolehmainen M, Silverman WK, et al. Preventing Childhood Obesity Through a Mindfulness-Based Parent Stress Intervention: A Randomized Pilot Study. J Pediatr. 2018;202:136–42 e1. doi: 10.1016/j.jpeds.2018.07.011 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref014] 14.Mindell JA, Kuhn B, Lewin DS, Meltzer LJ, Sadeh A, American Academy of Sleep M. Behavioral treatment of bedtime problems and night wakings in infants and young children. Sleep. 2006;29(10):1263–76. [PubMed] [Google Scholar]

[pone.0264514.ref015] 15.Hash JB, Oxford ML, Fleming CB, Ward TM, Spieker SJ. Sleep Problems, Daily Napping Behavior, and Social-Emotional Functioning among Young Children from Families Referred to Child Protective Services. Behav Sleep Med. 2020;18(4):447–59. doi: 10.1080/15402002.2019.1611579 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref016] 16.Copinschi G, Leproult R, Spiegel K. The important role of sleep in metabolism. Front Horm Res. 2014;42:59–72. doi: 10.1159/000358858 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref017] 17.Lunsford-Avery JR, Bidopia T, Jackson L, Sloan JS. Behavioral Treatment of Insomnia and Sleep Disturbances in School-Aged Children and Adolescents. Child Adolesc Psychiatr Clin N Am. 2021;30(1):101–16. doi: 10.1016/j.chc.2020.08.006 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref018] 18.Hall WA, Nethery E. What does sleep hygiene have to offer children’s sleep problems? Paediatr Respir Rev. 2019;31:64–74. doi: 10.1016/j.prrv.2018.10.005 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref019] 19.Wilson KE, Lumeng JC, Kaciroti N, Chen SY, LeBourgeois MK, Chervin RD, et al. Sleep Hygiene Practices and Bedtime Resistance in Low-Income Preschoolers: Does Temperament Matter? Behav Sleep Med. 2015;13(5):412–23. doi: 10.1080/15402002.2014.940104 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref020] 20.Olsen NJ, Angquist L, Frederiksen P, Lykke Mortensen E, Lilienthal Heitmann B. Primary prevention of fat and weight gain among obesity susceptible healthy weight preschool children. Main results from the "Healthy Start" randomized controlled intervention. Pediatr Obes. 2020:e12736. doi: 10.1111/ijpo.12736 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref021] 21.Handel MN, Larsen SC, Rohde JF, Stougaard M, Olsen NJ, Heitmann BL. Effects of the Healthy Start randomized intervention trial on physical activity among normal weight preschool children predisposed to overweight and obesity. PLoS One. 2017;12(10):e0185266. doi: 10.1371/journal.pone.0185266 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref022] 22.Rohde JF, Larsen SC, Angquist L, Olsen NJ, Stougaard M, Mortensen EL, et al. Effects of the Healthy Start randomized intervention on dietary intake among obesity-prone normal-weight children. Public Health Nutr. 2017;20(16):2988–97. doi: 10.1017/S1368980017002026 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref023] 23.Bliddal M, Broe A, Pottegard A, Olsen J, Langhoff-Roos J. The Danish Medical Birth Register. Eur J Epidemiol. 2018;33(1):27–36. doi: 10.1007/s10654-018-0356-1 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref024] 24.Cole TJ, Bellizzi MC, Flegal KM, Dietz WH. Establishing a standard definition for child overweight and obesity worldwide: international survey. BMJ. 2000;320(7244):1240–3. doi: 10.1136/bmj.320.7244.1240 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref025] 25.Prochaska JO, DiClemente CC. Stages and processes of self-change of smoking: toward an integrative model of change. J Consult Clin Psychol. 1983;51(3):390–5. doi: 10.1037//0022-006x.51.3.390 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref026] 26.Rollnick S, Butler CC, Kinnersley P, Gregory J, Mash B. Motivational interviewing. BMJ. 2010;340:c1900. doi: 10.1136/bmj.c1900 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref027] 27.Hitze B, Bosy-Westphal A, Bielfeldt F, Settler U, Plachta-Danielzik S, Pfeuffer M, et al. Determinants and impact of sleep duration in children and adolescents: data of the Kiel Obesity Prevention Study. Eur J Clin Nutr. 2009;63(6):739–46. doi: 10.1038/ejcn.2008.41 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref028] 28.Olsen NJ, Buch-Andersen T, Handel MN, Ostergaard LM, Pedersen J, Seeger C, et al. The Healthy Start project: a randomized, controlled intervention to prevent overweight among normal weight, preschool children at high risk of future overweight. BMC Public Health. 2012;12(1):590. doi: 10.1186/1471-2458-12-590 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref029] 29.SDQinfo.org [Internet] [Cited 2022 Mar 3] Available from https://www.sdqinfo.org/py/sdqinfo/c0.py.

[pone.0264514.ref030] 30.Goodman R. The Strengths and Difficulties Questionnaire: a research note. J Child Psychol Psychiatry. 1997;38(5):581–6. doi: 10.1111/j.1469-7610.1997.tb01545.x [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref031] 31.Obel C, Heiervang E, Rodriguez A, Heyerdahl S, Smedje H, Sourander A, et al. The Strengths and Difficulties Questionnaire in the Nordic countries. Eur Child Adolesc Psychiatry. 2004;13 Suppl 2:II32–II9. doi: 10.1007/s00787-004-2006-2 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref032] 32.Niclasen J, Teasdale TW, Andersen AM, Skovgaard AM, Elberling H, Obel C. Psychometric properties of the Danish Strength and Difficulties Questionnaire: the SDQ assessed for more than 70,000 raters in four different cohorts. PLoS One. 2012;7(2):e32025. doi: 10.1371/journal.pone.0032025 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref033] 33.Ostberg M, Hagekull B, Wettergren S. A measure of parental stress in mothers with small children: dimensionality, stability and validity. Scand J Psychol. 1997;38(3):199–208. doi: 10.1111/1467-9450.00028 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref034] 34.Gelman A, Carlin J. Beyond Power Calculations: Assessing Type S (Sign) and Type M (Magnitude) Errors. Perspect Psychol Sci. 2014;9(6):641–51. doi: 10.1177/1745691614551642 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref035] 35.Galland BC, Short MA, Terrill P, Rigney G, Haszard JJ, Coussens S, et al. Establishing normal values for pediatric nighttime sleep measured by actigraphy: a systematic review and meta-analysis. Sleep. 2018;41(4). doi: 10.1093/sleep/zsy017 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref036] 36.Williamson AA, Mindell JA, Hiscock H, Quach J. Sleep Problem Trajectories and Cumulative Socio-Ecological Risks: Birth to School-Age. J Pediatr. 2019;215:229–37 e4. doi: 10.1016/j.jpeds.2019.07.055 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref037] 37.Michels N, De Henauw S, Eiben G, Hadjigeorgiou C, Hense S, Hunsberger M, et al. Effect of the IDEFICS multilevel obesity prevention on children’s sleep duration. Obes Rev. 2015;16 Suppl 2:68–77. doi: 10.1111/obr.12327 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref038] 38.Wing YK, Chan NY, Man Yu MW, Lam SP, Zhang J, Li SX, et al. A school-based sleep education program for adolescents: a cluster randomized trial. Pediatrics. 2015;135(3):e635–43. doi: 10.1542/peds.2014-2419 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref039] 39.Taylor RW, Gray AR, Heath AM, Galland BC, Lawrence J, Sayers R, et al. Sleep, nutrition, and physical activity interventions to prevent obesity in infancy: follow-up of the Prevention of Overweight in Infancy (POI) randomized controlled trial at ages 3.5 and 5 y. Am J Clin Nutr. 2018;108(2):228–36. doi: 10.1093/ajcn/nqy090 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref040] 40.Fatima Y, Doi SA, Mamun AA. Longitudinal impact of sleep on overweight and obesity in children and adolescents: a systematic review and bias-adjusted meta-analysis. Obes Rev. 2015;16(2):137–49. doi: 10.1111/obr.12245 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref041] 41.Pesonen AK, Sjosten NM, Matthews KA, Heinonen K, Martikainen S, Kajantie E, et al. Temporal associations between daytime physical activity and sleep in children. PLoS One. 2011;6(8):e22958. doi: 10.1371/journal.pone.0022958 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref042] 42.Hruska V, Darlington G, Haines J, Ma DWL. Parent Stress as a Consideration in Childhood Obesity Prevention: Results from the Guelph Family Health Study, a Pilot Randomized Controlled Trial. Nutrients. 2020;12(6). [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref043] 43.O’Connor SG, Maher JP, Belcher BR, Leventhal AM, Margolin G, Shonkoff ET, et al. Associations of maternal stress with children’s weight-related behaviours: a systematic literature review. Obes Rev. 2017;18(5):514–25. doi: 10.1111/obr.12522 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref044] 44.Jang M, Brown R, Vang PY. The Relationships Between Parental Stress, Home Food Environment, and Child Diet Patterns in Families of Preschool Children. Am J Health Promot. 2021;35(1):131–9. [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref045] 45.Jang M, Owen B, Lauver DR. Different types of parental stress and childhood obesity: A systematic review of observational studies. Obes Rev. 2019;20(12):1740–58. doi: 10.1111/obr.12930 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref046] 46.Lumeng JC, Miller AL, Horodynski MA, Brophy-Herb HE, Contreras D, Lee H, et al. Improving Self-Regulation for Obesity Prevention in Head Start: A Randomized Controlled Trial. Pediatrics. 2017;139(5). doi: 10.1542/peds.2016-2047 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref047] 47.Cooke D, Marais I, Cavanagh R, Kendall G, Priddis L. Differences Between Mothers’ and Fathers’ Ratings of Family Functioning With the Family Assessment Device. Measurement and Evaluation in Counseling and Development 2015;48(3). [Google Scholar]

[pone.0264514.ref048] 48.Marsman R, Swinkels SH, Rosmalen JG, Oldehinkel AJ, Ormel J, Buitelaar JK. HPA-axis activity and externalizing behavior problems in early adolescents from the general population: the role of comorbidity and gender The TRAILS study. Psychoneuroendocrinology. 2008;33(6):789–98. doi: 10.1016/j.psyneuen.2008.03.005 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref049] 49.Tyrka AR, Kelly MM, Graber JA, DeRose L, Lee JK, Warren MP, et al. Behavioral adjustment in a community sample of boys: links with basal and stress-induced salivary cortisol concentrations. Psychoneuroendocrinology. 2010;35(8):1167–77. doi: 10.1016/j.psyneuen.2010.02.002 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref050] 50.Ouellet-Morin I, Odgers CL, Danese A, Bowes L, Shakoor S, Papadopoulos AS, et al. Blunted cortisol responses to stress signal social and behavioral problems among maltreated/bullied 12-year-old children. Biol Psychiatry. 2011;70(11):1016–23. doi: 10.1016/j.biopsych.2011.06.017 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref051] 51.Hatzinger M, Brand S, Perren S, von WA, von KK, Holsboer-Trachsler E. Hypothalamic-pituitary-adrenocortical (HPA) activity in kindergarten children: importance of gender and associations with behavioral/emotional difficulties. J Psychiatr Res. 2007;41(10):861–70. doi: 10.1016/j.jpsychires.2006.07.012 [DOI] [PubMed] [Google Scholar]

[pone.0264514.ref052] 52.Ruttle PL, Shirtcliff EA, Serbin LA, Fisher DB, Stack DM, Schwartzman AE. Disentangling psychobiological mechanisms underlying internalizing and externalizing behaviors in youth: longitudinal and concurrent associations with cortisol. Horm Behav. 2011;59(1):123–32. doi: 10.1016/j.yhbeh.2010.10.015 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref053] 53.Abulizi X, Pryor L, Michel G, Melchior M, van der Waerden J, Group EM-CCS. Temperament in infancy and behavioral and emotional problems at age 5.5: The EDEN mother-child cohort. PLoS One. 2017;12(2):e0171971. doi: 10.1371/journal.pone.0171971 [DOI] [PMC free article] [PubMed] [Google Scholar]

[pone.0264514.ref054] 54.Parkes A, Green M, Mitchell K. Coparenting and parenting pathways from the couple relationship to children’s behavior problems. J Fam Psychol. 2019;33(2):215–25. doi: 10.1037/fam0000492 [DOI] [PMC free article] [PubMed] [Google Scholar]

PERMALINK

Effects of the healthy start randomized intervention on psychological stress and sleep habits among obesity-susceptible healthy weight children and their parents

Nanna Julie Olsen

Sofus Christian Larsen

Jeanett Friis Rohde

Maria Stougaard

Mina Nicole Händel

Ina Olmer Specht

Berit Lilienthal Heitmann

Roles

Abstract

Introduction

Methods and materials

Fig 1. Flow chart.

The intervention

Ethics

Outcomes

Child behavioral problems

Parenting stress

Sleep habits

Covariates for multiple imputations

Statistical methods

Modified intention-to-treat analyses

Sensitivity analyses

Results

Table 1. Baseline characteristics of the included participants stratified by intervention status1.

Child behavioral problems

Table 2. Changes in sleep and stress between baseline and follow-up (1.3 years).

Parenting stress

Sleep habits

Discussion

Conclusion

Supporting information

Acknowledgments

Data Availability

Funding Statement

References

Decision Letter 0

Lee Van Horn

Roles

Author response to Decision Letter 0

Decision Letter 1

Lee Van Horn

Roles

Author response to Decision Letter 1

Decision Letter 2

Lee Van Horn

Roles

Acceptance letter

Lee Van Horn

Roles

Associated Data

Supplementary Materials

Data Availability Statement

ACTIONS

PERMALINK

RESOURCES

Similar articles

Cited by other articles

Links to NCBI Databases

Table 1. Baseline characteristics of the included participants stratified by intervention status¹.