Association between Home Environment in Infancy and Child Movement Behaviors

Abstract

Introduction: An adequate balance of movement behaviors, including physical activity (PA), sleep, and screen time, is important for preventing excess weight gain in children. This study examined the relationship between the infant home environment and movement behaviors later in life.

Methods: Pregnant women were recruited for a cohort study related to maternal and child development. The home environment was assessed for developmental stimulation, organization, and toys by the Pediatric Review of Children's Environmental Support and Stimulation (PROCESS) questionnaire when the child was 6 months of age. At 2 years of age, mother-reported child screen time, and child PA and sleep duration were estimated by accelerometry. Child behaviors were compared with the 24-hour Movement Guidelines (≥180 minutes/day of total PA, 11–14 hours/day of sleep, and ≤1 hour/day of screen time). Logistic regression was used to assess the relationship between the home environment and movement behaviors, adjusting for maternal and child covariates.

Results: Mother/child dyads (n = 141) were mainly white (84.4%), and middle (32.8%) or low income (48.9%). All children (100%) met the PA guideline, some met the sleep guideline (71.6%), fewer met the screen-time guideline (44.7%), and only one-third (34.0%) met all three guidelines. Children who met the screen-time guideline lived in homes with more developmental stimulation and toys (p < 0.05). Children who met all 3 guidelines lived in homes with more organization and toys (p < 0.05).

Conclusion: The infant home environment was associated with appropriate amounts of movement behaviors at 2 years. Promoting organization (i.e., routines) and toys in infancy may help facilitate nonscreen-based habits and healthy development. The clinical trial registration number is NCT01131117.

Background

An appropriate balance of physical activity (PA), sleep, and sedentary behavior is crucial for child physical and mental development.^1–3 Low levels of PA, inadequate sleep, and high amounts of sedentary behavior (e.g., sedentary screen time) may promote early childhood obesity.^4,5 The 24-hour Movement Guidelines were created to acknowledge the beneficial impact of an appropriate balance of all three behaviors,⁶ and these guidelines were recently adopted by the World Health Organization (WHO).⁷ Few toddlers (ages 1–2 years, 11%)⁸ or preschoolers (ages 3–4 years, 11%–15%)^9,10 meet all three guidelines, mainly due to high amounts of screen time. Innovative and timely approaches to help children obtain adequate amounts of all three behaviors may support long-term health and child development.

From infancy, an important influence on child movement is the home environment.¹¹ The home environment encompasses multiple components, including parental involvement, household organization (i.e., routine), and the physical environment (e.g., toys), which are each related to preschooler's movement. Parental involvement in PA is associated with more child PA,¹² while a disorganized home may promote more screen time¹³ and bedtime resistance.¹⁴ Additional home space is related to more PA,¹⁵ and more toys in the home is associated with less screen time.¹⁵ Considering these relationships, it may be hypothesized that movement behaviors are interrelated within the home, such that decreasing screen time before bedtime may lead to more sleep.¹⁶ Evaluating the relationship between home environment characteristics and child movement could identify the contribution of the home environment to an adequate balance of all three behaviors.

Creating a healthy home environment in infancy is critical, as home characteristics in early infancy (6-months) may remain constant into toddlerhood.¹⁷ Early home-based interventions for feeding behaviors and parenting are beneficial in establishing healthy eating habits in later infancy.^18,19 As for movement behaviors, a nurse-led intervention focusing on increasing tummy time (awake time spent on an infant's stomach) and limiting screen time within the first 10 months resulted in less screen time at 12 months, but changes were not evaluated into toddlerhood.²⁰ Examining early home factors and future child movement may provide targets for home-based interventions. Therefore, the purpose of this study was to examine the relationship between the home environment at 6 months old and child movement behaviors and attainment of the 24-hour Movement Guidelines at 2 years old.

Methods

Participants

Mothers in their first trimester or attempting to become pregnant were recruited for a prospective observational cohort related to maternal and child development (GLOWING Study, NCT01131117) between 2011 and 2014. Recruitment was in various forms, including flyers, in-person events at medical offices, health fairs, child care centers, and other local venues. Mothers who had a BMI between 18.5 and 35.0 kg/m² at the baseline visit, were in their second pregnancy, had a singleton pregnancy, >21 years of age, and conceived the child without fertility treatments were eligible for inclusion. Infants who were born at ≥37 weeks of gestation were included for measurements from birth to 2 years of age. Mothers were excluded at enrollment for preexisting medical conditions, medical complications, and use of medications that may influence fetal growth during pregnancy, smoking, alcohol consumption, and exceptional PA (e.g., athletes). Children were excluded at birth and other time points for medical conditions and use of medications related to child growth.

The GLOWING Study was powered to detect a statistically significant difference in weight-for-length percentiles at 3 months between infants born to mothers of normal weight and overweight (n = 65 per group, 130 total). Phone calls, letters, and e-mail contacts helped facilitate continued participation in the study through 2 years. The current report utilized baseline data, and data at postnatal age 6 months and 2 years and follows the STROBE Reporting guidelines for cohort studies (Supplementary Table S1). The University of Arkansas for Medical Sciences Institutional Review Board approved this study, and procedures were in accordance with the Helsinki Declaration of 1975.

Procedures

At the baseline visit, mothers provided informed consent and completed demographic questions on age, race, household income, and number of parents present at home. Height (cm) and weight (kg) of mothers were objectively measured to the nearest 0.1 U by a trained researcher, and BMI (kg/m²) was calculated. Mothers reported child birthweight (lbs and ounces) at their first postnatal visit (∼2 weeks). At the 6-month postnatal visit, mothers completed a questionnaire to assess the home environment. At the 2-year visit, mothers reported screen-time habits, child anthropometrics were measured, and free-living child PA and sleep were measured using an accelerometer (Actical, Philips Respironics, Bend, OR). The child's BMI z-score for age and sex was calculated using national growth standards.²¹

Home Environment and Screen Time

Home environment was assessed using the Pediatric Review of Children's Environmental Support and Stimulation (PROCESS) questionnaire.²² This questionnaire was completed by the mother and includes 25 questions across 3 domains of parental involvement and developmental stimulation (14 questions), household organization and predictability (10 questions), and available toys within the home (given 40 options). The PROCESS questionnaire is a reliable measure with demonstrated internal consistency (alpha = 0.61–0.72). The household organization domain (range: 0.73–0.86) and developmental stimulation domain (range: 0.35–0.69) are correlated other home inventories and direct observation of parent and child interaction.

Questions are scored 1–4, with a higher score indicating more parental involvement and a more predictable home environment. The sum of selected toys was assigned a component score ranging from 0 to 8 based on 5-toy increments (i.e., 1–5 toys is a score of 1), which was multiplied by 6 for a weighted toy score. The total environment score was the sum of developmental stimulation, household organization, and weighted toy scores.

At the 2-year visit, mothers reported their child's screen-viewing habits, which were used to represent sedentary behavior. The questionnaire asked, “How many hours per day did your child watch television or videos in the past week?” with options of 0 or increasing 1-hour increments until 15 hours, similar to national screen-time reports.²³

PA and Sleep

PA and sleep were assessed over 7 days using an accelerometer attached to the ankle with a tight-fitting adjustable medical band. Data were recorded in 15-second epochs and converted to 60-second epochs for detection of sleep, nonwear, and activity wear-time. The Sadeh algorithm was used to identify sleep periods, and time spent asleep and wake within these periods.²⁴ Nighttime sleep periods were defined as sleep periods occurring between 8:00 pm and 8:00 am as used in other toddler studies.^25,26 This time frame aligns with an average toddler bedtime between 8:00 and 9:00 pm and wake-time between 7:00 and 8:00 am.^27,28 Daytime sleep periods of ≥30 minutes that occurred between 9:00 am and 5:00 pm were defined as naps. Time in bed was the difference between algorithm-determined bedtime and wake-time of the sleep periods, including asleep and wake epochs. Total sleep duration consisted of asleep epochs in nap and nighttime sleep periods. Nighttime sleep efficiency was the proportion of time in bed during the night classified as asleep.

Nonwear periods for daytime activity were defined as any remaining periods of ≥20 minutes of continuous zeroes after sleep detection,^29,30 and were removed for PA analysis. Using established age-appropriate cut-points for ankle accelerometry,³¹ the remaining wear-time was classified into sedentary (<40 counts/min), light PA (40–2200 counts/min), and moderate-to-vigorous physical activity [(MVPA), >2200 counts/min]. Total PA was the sum of light PA and MVPA. Children with ≥10 hours/day of activity wear-time and recorded nighttime sleep for ≥3 days were included in the analysis, consistent with previous research.³² For each day, the percent of time spent in each intensity (sedentary, light, and MVPA) was calculated and averaged across valid days (≥10 hours of wear-time).

Movement Guidelines

Child movement behaviors were defined as mother-reported screen time for sedentary behavior and accelerometry-measured total PA and total sleep duration at the 2-year visit. Movement behaviors were classified according to the WHO 24-hour Movement Guidelines for this age,⁷ including recommended amounts of PA (≥180 minutes/day), sleep (11–14 hours/day), and sedentary behavior (≤1 hour/day screen time).^7,25 The number of guidelines met was summed (possible range: 0–3). As all children met the PA guideline in this sample (100%), a median-split was conducted to compare home environment scores between children with less (below the median) or more (above the median) total PA as conducted by others.³³

Data Analysis

Mother/child dyads with complete data (demographics, PROCESS questionnaire, accelerometry, and screen time) were included in the analysis. Differences between individuals included and not included were conducted using an independent t-test and chi-square analysis. Pearson correlation coefficients were calculated among independent variables (PROCESS scores of developmental stimulation, household organization, weighted toy, and total environment at 6 months) and dependent variables of PA and sleep. Spearman's rank correlation coefficients were calculated due to non-normal distribution of the association between PROCESS scores and screen time. Pearson correlation coefficients were conducted among dependent variables.

Linear regression was used to assess the relationship between independent variables and dependent variables and checked for assumptions of normality. Models were adjusted for covariates of maternal BMI, maternal age at childbirth, race, number of parents in the household, household income, child sex, birthweight, and BMI z-score at the 2-year visit. Models were also adjusted for other behaviors such as other 24-hour Movement Guideline investigations and to account for all movement behaviors.^34,35

As for guidelines attained, one-way analysis of variance was used to compare home environment scores by meeting individual guidelines and median split for PA, along with number of guidelines met. A Tukey post hoc test was conducted for pair-wise comparisons. Logistic regression was used to assess the relationship between independent variables and guideline attainment (PA median split, sleep, screen time, and all three guidelines), with adjustment for the same covariates as the linear regression models and the other guidelines (i.e., the sleep model was also adjusted for PA median split and screen time). All statistical analyses were conducted using SAS 9.4 software (Cary, NC), and significance was set at p < 0.05.

Results

Study Sample

In total, 263 mothers completed the baseline visit, 217 mothers completed the 6-month visit; and 195 children completed the 2-year visit. Of the 195 who attended the 2-year visit, 53 participants (27.2%) were missing PA data from not wearing the device (n = 17, 8.7%) or had inadequate wear (n = 36, 18.4%). One remaining participant did not have adequate sleep data; thus, 141 mother/child dyads were included in the analysis.

Compared with those not included at any stage, included mothers had a lower BMI (25.4 ± 4.2 vs. 26.7 ± 4.2 kg/m², respectively, p = 0.01) and more identified as white (84.4% vs. 62.3%, respectively, p = 0.01). Included children had slightly lower developmental stimulation scores (45.5 ± 3.3 vs. 46.8 ± 3.9, respectively, p = 0.01) and performed more total PA (556.7 ± 69.4 vs. 527.8 ± 51.1 minutes/day, respectively, p = 0.03, data not shown).

Among the dyads included in the study, mothers were 30.4 ± 3.5 years of age at the child's birth, and middle ($60,000–$89,999, 32.8%) or low income (<$59,999, 48.9%, Table 1). Developmental stimulation and household organization scores had an average response of 3.2 ± 0.2 and 3.1 ± 0.2 out of 4, respectively, which indicates that parents were occasionally involved in the child's development and households were somewhat organized. Generally, children exceeded the guideline of 180 minutes/day of total PA (556.6 ± 69.4 minutes/day), slept within the recommended range of 10–13 hours/day (11.4 ± 0.7 hours/day), and surpassed the sedentary behavior guideline of ≤1 hour/day of screen time (2.4 ± 2.2 hours/day). All children met the PA guideline (100%); thus, all children met at least one guideline. About half met two guidelines (48.2%), and one-third met all three guidelines (34.0%). Most of those who met two guidelines met the sleep guideline (n = 53, 77.9%), rather than the screen-time guideline (n = 15, 22.1%).

Table 1.

Descriptive Characteristics of Sample (n = 141)

	Mean	SD	%
Maternal characteristics
Age at childbirth (years)	30.4	3.5
Race
White			84.4
African American			10.7
Other			4.9
Prepregnancy BMI (kg/m2)	25.4	4.2
Household income
Less than $59,999			48.9
$60,000–89,999			32.8
$90,000 or greater			18.3
Parents present in home	1.9	0.2
Home environment at 6 months
Developmental stimulation score (range 14–56)	45.5	3.3
Household organization score (range 10–40)	31.0	2.2
Number of toys (range 0–40)	20.5	8.4
Weighted toy score (range 0–48)	26.9	10.2
Total environment score (24–144)	103.5	11.8
Child characteristics
Male			56.4
Race
White			84.4
African American			10.6
Other			5.0
Birthweight (lbs)	7.8	1.0
BMI (kg/m2) at 2 years	16.6	1.3
BMI z-score at 2 years	−0.02	0.95
Child movement behaviors at 2 years
Days of valid wear for PA, days	5.5	1.4
PA wear-time, hours/day	11.9	1.1
Total PA, minutes/day	556.6	69.4
Light PA	500.1	64.8
MVPA	56.5	32.9
Percent time in each intensity, average/day
Sedentary	22.7	4.4
Light PA	70.0	4.5
MVPA	7.3	3.5
Sleep, hours/day	11.4	0.7
Nighttime sleep, hours/day	9.5	0.7
Daytime sleep/nap, hours/day	2.3	0.6
Time in bed, hours/day	11.8	0.7
Nighttime sleep efficiency, percent	97.2	1.2
Screen time, hours/day	2.4	2.2
Individual guidelines met
Total PA			100.0
Sleep			71.6
Screen time			44.7
Number of guidelines met
1			17.7
2			48.2
3			34.0

BMI, body mass index; MVPA, moderate-to-vigorous physical activity; PA, physical activity; SD, standard deviation.

Movement Behaviors

As shown in Table 2, developmental stimulation score at 6 months was negatively correlated with total sleep, nighttime sleep efficiency, and screen time at 2 years (p < 0.05 for all). Household organization score was negatively associated with light PA (minutes), but positively associated with total sleep and time in bed (p < 0.05 for all). Total environment score was positively associated with MVPA (percent time), and both weighted toy and total environment scores were negatively associated with screen time (p < 0.001 for all). Total PA and light PA were negatively correlated with total sleep (r = −0.44, p < 0.001 for both), time in bed (r = −0.42, p < 0.001 for both), and nighttime sleep efficiency (r = −0.20 and r = 0.18, respectively, ps < 0.001 for both). Screen time was not correlated with any PA or sleep variable.

Table 2.

Correlation Coefficients between Home Environment Scores at 6 Months and Movement Behaviors at 2 Years^a

Movement behaviors at 2 years	Home environment scores at 6 months
	Developmental stimulation	Household organization	Weighted toy	Total environment
PA
Sedentary, minutes	0.01	−0.06	−0.01	−0.02
Light PA, minutes	0.05	−0.18*	−0.03	−0.04
MVPA, minutes	−0.02	0.06	0.14	0.13
Total PA, minutes	0.04	−0.14	0.04	0.02
Sedentary, percent time	0.02	−0.07	−0.01	0.01
Light PA, percent time	−0.03	−0.05	−0.13	−0.13
MVPA, percent time	0.01	0.15	0.15	0.16*
Total PA, percent time	−0.02	0.07	−0.01	−0.01
Sleep
Sleep, hours/day	−0.18*	0.17*	0.08	0.05
Time in bed, hours/day	−0.14	0.18*	0.10	0.08
Nighttime sleep efficiency, percent	−0.25**	−0.03	−0.06	−0.13
Screen time, hours/dayb	−0.17*	−0.11	−0.32***	−0.36***

^*p < 0.05, ^**p < 0.01, ^***p < 0.001.

^aAssessed using Pearson's correlation coefficients.

^bAssessed using Spearman's rank correlation coefficients due to non-normal distribution of association.

After adjustment for covariates, there were mixed relationships between home environment and sleep. Developmental stimulation score at 6 months was negatively associated with total sleep (β = −0.01, SE = 0.01, p = 0.02) and nighttime sleep efficiency (β = −0.09, SE = 0.03, p = 0.001). Developmental stimulation (β = −0.17, SE = 0.05, p = 0.003), weighted toy (β = −0.04, SE = 0.01, p = 0.01), and total environment scores (β = −0.05, SE = 0.01, p = 0.001) were associated with less screen time after adjustment. There were no associations between home environment and PA in adjusted models (p > 0.05).

Individual Behavior Guidelines and Number of Guidelines Met

Children who met the screen-time guideline at 2 years had higher scores for each home environment domain at 6 months compared with children who did not meet the screen-time guideline (p < 0.05 for all, Table 3). In individual models, the total environment score explained 14% of the variance for meeting the screen-time guideline, and weighted toy score explained 10% of the variance. Developmental stimulation (4%) and household organization (3%) explained less variance in individual models. Children who met the screen-time guideline had a total environment score that was 8.9 ± 12.5 U higher, equivalent to over five additional toys or parents being very involved rather than not involved in two or more developmentally stimulating activities. Children who met all three guidelines had significantly higher household organization, weighted toy, and total environment scores compared with children who met two guidelines and children who met one guideline (p < 0.05 for each comparison).

Table 3.

Comparison of Home Environment Scores at 6 Months by Physical Activity, Individual Guidelines, and Number of Guidelines Met at 2 Years (n = 141)^a

	Movement behaviors at 2 years
	PA median split				Sleep guideline
	Less PA (n = 70)	More PA (n = 71)			Did not meet (n = 40)	Met (n = 101)
	Mean ± SD	Mean ± SD	p	R2	Mean ± SD	Mean ± SD	p	R2
Home environment scores at 6-months
Developmental stimulation	45.2 ± 3.2	45.9 ± 3.4	0.20	0.01	46.2 ± 3.8	45.3 ± 3.1	0.15	0.01
Household organization	31.2 ± 2.2	30.8 ± 2.3	0.18	0.01	30.4 ± 2.2	31.2 ± 2.2	0.07	0.02
Weighted toy	26.6 ± 9.7	27.2 ± 10.8	0.74	0.00	26.4 ± 10.8	27.2 ± 10.0	0.69	0.01
Total environment	103.2 ± 11.0	103.8 ± 12.7	0.70	0.00	103.1 ± 12.7	103.7 ± 11.5	0.78	0.01
	Screen-time guideline				Number of guidelines met
	Did not meet (n = 78)	Met (n = 63)			One guideline (n = 25)	Two guidelines (n = 68)	Three guidelines (n = 48)
	Mean ± SD	Mean ± SD	p	R2	Mean ± SD	Mean ± SD	Mean ± SD	p	R2
Developmental stimulation	45.0 ± 3.3	46.2 ± 3.2	0.02*	0.04	45.6 ± 4.2	45.2 ± 3.0	46.1 ± 3.2	0.31	0.01
Household organization	30.6 ± 2.3	31.4 ± 2.2	0.02*	0.03	30.4 ± 2.1	30.7 ± 2.4	31.7 ± 2.1	0.01*	0.05
Weighted toy score	23.8 ± 10.3	30.6 ± 8.9	0.001*	0.10	25.4 ± 11.2	24.3 ± 10.4	31.5 ± 8.8	0.009*	0.10
Total environment	99.5 ± 11.4	108.4 ± 10.4	0.001*	0.14	101.5 ± 13.9	100.4 ± 11.3	109.3 ± 10.4	0.003*	0.13

^*p < 0.05.

^aAssessed using one-way analysis of variance with respective R²; as all children met PA guideline, no comparison of meeting PA guideline was conducted and the range for number of guidelines met is 1–3.

Higher developmental stimulation, weighted toy, and total environment scores at 6 months were related to increased odds of meeting the screen-time guideline at 2 years in adjusted models (p < 0.05 for all, Table 4). Higher household organization, weighted toy, and total environment scores also resulted in greater odds of meeting all three guidelines compared with meeting two or one guideline (p < 0.05 for all).

Table 4.

Adjusted Odds of Meeting Individual Guidelines and Number of Guidelines Met at 2 Years from Home Environment Scores at 6 Months (n = 141)^a

Home environment scores at 6 months	Movement guidelines at 2 years
	PA median split			Sleep guideline
	OR	95% CI	p	OR	95% CI	p
Developmental stimulation	1.05	0.95–1.22	0.20	0.89	0.78–1.02	0.11
Household organization	0.91	0.78–1.08	0.32	1.14	0.95–1.37	0.14
Weighted toys	0.99	0.96–1.04	0.74	0.99	0.95–1.04	0.99
Total environment	1.00	0.97–1.04	0.65	0.99	0.96–1.03	0.86
	Screen-time guideline			Meeting all three guidelines
	OR	95% CI	p	OR	95% CI	p
Developmental stimulation	1.19	1.06–1.37	0.005*	1.12	0.98–1.28	0.08
Household organization	1.15	0.97–1.36	0.12	1.21	1.01–1.45	0.04*
Weighted toys	1.07	1.03–1.11	0.001*	1.11	1.02–1.11	0.005*
Total environment	1.08	1.04–1.12	<0.001*	1.07	1.03–1.11	0.001*

^*p < 0.05.

^aMeeting all three guidelines includes meeting PA guideline, not PA median split. Assessed using logistic regression with adjustment for mother's age at childbirth, maternal race, maternal BMI, number of parents working full-time, household income, child gender, child BMI z-score, birthweight, and meeting other guidelines.

Discussion

In this study, multiple components of the home environment in infancy were related to toddler movement behaviors. Children who lived in a more organized household with access to more toys in infancy had a higher likelihood of meeting all three movement behavior guidelines at 2 years. This study contributes to the evidence that home characteristics in infancy are related to future child movement, namely less screen time. Improvements in the infant's home environment may encourage an appropriate balance of movement and healthful development.

Children in this study were sufficiently active (100% met PA guideline) and engaged in ∼1 hour of MVPA daily (56.5 ± 32.9 minutes/day), which is comparable with cross-sectional studies of device-based PA in toddlers (100% met guideline, and 54.5–58.0 minutes/day of MVPA).^25,33 The light PA levels are quite high relative to preschoolers (ages 3–4 years) using the same device (213 minutes of light PA), potentially due to differing device placement and cut-points.³⁶ The current sample had a high nighttime sleep efficiency (97.2% ± 1.2%), and many met the sleep guideline (71.4%). These results contrast with a low-income sample of toddlers who used similar methods but had a lower guideline attainment (32%) and nighttime sleep efficiency (80.0% ± 9.0%).²⁵

The early home environment was not related to toddler PA and sleep after adjustment for covariates, suggesting that other factors may account for these behaviors. Outdoor time and sleep arrangement may result in beneficial PA³⁷ and sleep in toddlerhood,³⁸ respectively, and these components of the home environment may form in later infancy and toddlerhood. Regardless, a more favorable home environment, including more organization and toys, at 6 months was associated with meeting all three guidelines. Encouraging a healthier home may facilitate other family behaviors that support adequate PA and sleep.

The current study reported a higher proportion of children meeting the screen-time guideline (44.7%) compared with other observational studies in toddlers (11%–15.2%),^8,33 as these studies have considered devices beyond television (i.e., tablet or cell phone).^8,33 This difference in measurement may also explain a larger proportion of the current sample meeting all three guidelines (34%) compared with others (11%–15%).^8–10 The amount of screen time in the current study (2.4 ± 2.2 hours/day) is similar to a slightly older sample (2.1 ± 1.1 hours/day, age 19–60 months),³⁹ and television is the most common form of screen time in toddlers and preschoolers.^8,10 Children who lived in more organized households in infancy were more likely to meet the screen-time guideline in toddlerhood. In a slightly older sample of 385 children (ages 2–5 years), children who lived in higher chaos households, characterized by noise, crowding, and disarray, had more screen time compared with lower chaos households.¹³ The current study adds to evidence that this relationship begins before preschool, specifically that household organization during infancy is associated with less screen time in toddlerhood.

This study also found that the number of toys in infancy is related to future screen habits, which aligns with a cross-sectional study of 532 preschoolers that found children who met the screen-time guideline had more toys compared with children who did not meet the screen-time guideline.¹⁵ Toys in infancy may indicate an early pattern of toy-based play and nonscreen-based habits (e.g., quiet play). Toys may also promote engagement in other behaviors, such as tummy time, a component of the 24-hour Movement Guidelines for infants⁴⁰ associated with early child mobility.⁴¹ It is recommended that tummy time be performed with toys so this time is more enjoyable for the child and parent.⁴² Examining the types of toys used and play surrounding these toys in infants may provide additional context and modifiable targets for forming nonscreen-based habits.

Routines and toy-based play are important components of the home environment, and these components were related to less screen time. Other home-based interventions for early child development have mainly focused on responsive parenting and feeding behaviors.^18,19,43 Those interventions resulted in healthy feeding habits in toddlerhood,^18,19,43 with one reporting few differences in screen time compared with controls at 2.5 years,⁴³ and another reporting a minor effect on screen time at 3 years.¹⁸ Family routines may be a viable option, including bedtime routines and limiting nighttime screen use, which were related to less screen time, more sleep, and lower child BMI in a home-based intervention of 121 parent/child dyads (ages 2–5 years).¹⁶ Understandably, routine within the first year may be difficult, but encouraging proper sleep hygiene (e.g., bedtime routine) may promote beneficial sleep and less screen time.⁴⁴ Sleep hygiene and routines may complement other behavioral targets, such as breastfeeding, family meals, and bottles in bed, for early obesity prevention efforts.

This study is notable for several strengths, including a longitudinal study design, a validated questionnaire for the home environment, and device-based PA and sleep. The current study used a previously validated protocol for device-based measurement,³¹ although recognizes there are varying standards for PA and sleep assessment in toddlers for devices, placement, and PA intensity cut-points.⁴⁵ This study was specific to the home environment and did not consider screen time beyond television and from other settings (e.g., child care),⁴⁶ although most child cares have little or no screen time for toddlers.⁴⁷ Measures from the current study could be improved upon through detailed measures of screen time (i.e., 15- or 30-minute increments) and serial assessments of home environment (i.e., an assessment at 2 years) as the home environment may change over time.

The current sample had an average BMI z-score, slightly lower than a low-income sample in the United States (0.4 ± 1.1)²⁵ and included children who were more active and mothers had a lower BMI relative to dyads not included, which may indicate a healthier lifestyle. Accordingly, this sample was predominantly white and middle or low income, and results may not be generalizable to other populations. Furthermore, characterizing the home environment among first-time parents and child movement behavior may add to the understanding of this relationship, as the current study was exclusive to second-born children.

Overall, several components of the early home environment were associated with meeting all three movement behavior guidelines in toddlerhood. Results of this study support early adoption of routines and toys to encourage a healthy balance of movement behaviors. Additional investigation into early sleep hygiene, involvement with toys, and other household correlates of toddler PA may provide actionable targets for intervention. Supporting families in creating a healthy home environment in infancy, characterized by more organization and toys, may help children obtain adequate PA, sleep, and screen time in the future.

Disclaimer

The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. The funder/sponsor did not participate in the work.

Funding Information

This work was supported by USDA-ARS Project Plan 6026-51000-010-05S. The National Institute Health provided grants that supported CLK (T32DK064584), AA (R01 DK107516), and LMR (R01NR017644; R01DK124806).

Author Disclosure Statement

No competing financial interests exist.

Supplementary Material

Supplementary Table S1