Cognitive Behavior–Based Programming to Increase Physical Activity and Control Overweight/Obesity in Youth: An 18-Year Research Program Informing Novel Curricula

Abstract

Introduction

Because only 42% of elementary school–aged children and 8% of adolescents complete the recommended amount of physical activity, programs beyond physical education are required to address this inadequacy and the associated rise in overweight/obesity.

Objective

Our 18-year research program, conducted through the lens of accepted behavioral theory, field-based investigations, and predictive models intended to shape programs to address physical inactivity and high body mass index in youths, was reviewed.

Results

In research-to-practice task 1, studies evaluated a cognitive-behavioral elementary afterschool treatment developed from principles of social cognitive theory. It provided exercise/physical activity through an individualized goal-setting perspective and training in self-regulatory skills such as restructuring unproductive self-talk. In task 2, the research program focused on favorable associations between treatment-induced improvements in physical self-concept, the overall self, physical appearance, exercise-related self-efficacy, and mood; it also focused on increased physical activity and reductions in excess weight. Program adaptations for preschool and middle school were also found productive. As the treatment model was extended in research-to-practice task 3, a refined focus on self-regulation, self-efficacy, and mood yielded findings of enhanced effects. In task 4, protocol adaptations intended for youths with severe obesity, additional diabetes risks, and candidacies for bariatric surgery were reported. Finally, the reviewed research evaluated treatment adjuncts that incorporate technology.

Conclusion

Our program of field research yielded progress on physical inactivity and high body mass index in youths via psychosocial pathways. Findings suggested medical professionals more strongly attend to physical inactivity and weight issues in their young patients while seeking evidence-based methods to induce ongoing behavioral progress.

Introduction

The prevalence of overweight (body mass index [BMI; kg/m²] between the 85th and 94.9th percentile on sex- and age-adjusted growth charts) ¹ and obesity (BMI ≥ 95th percentile) in youths is currently a worldwide problem. ² In the United States, specifically, data indicate that 35% of children and adolescents are either overweight or obese, and 19% have obesity. ³ Being overweight/obese increases probabilities for health risks such as hypertension, type 2 diabetes mellitus, dyslipidemia, orthopedic problems, sleep apnea, and psychosocial problems throughout a person’s lifespan. ⁴ The prevalence of excess weight increases with age in young patients and is marginally greater in boys. ³ Obesity in those who are 2–19 years of age has more than tripled in the United States (US) since the 1970s, and is highest among Hispanic and Black children. ³

Although there have been inconsistencies in its measurement, physical activity is a robust predictor of weight status in youths (ie, more physical activity results in fewer overweight/obese children), and boys tend to be more active than girls. ^5,6 Although recommendations are for youths to complete a minimum of 60 minutes of moderate-to-vigorous physical activity/exercise per day to have a positive effect on their health, ⁷ a benchmark of at least 300 minutes per week has also been incorporated. ⁸ When objectively measured using accelerometry in a review of 20 studies across 10 countries (27,636 participants, age range of 9–13 years), adequate levels of physical activity were uniformly low but varied considerably (range of 1–12% for girls and 6–30% for boys). ⁵ Data indicate that US girls had the lowest percentage of completing recommended amounts of physical activity across the countries studied, and boys were second from the bottom. ⁵ Accelerometer data from the National Health and Nutritional Examination Survey in the US indicated that for youths aged 6–11 years, 42% completed recommended weekly amounts of physical activity (35% of girls, 49% of boys), and for both the age ranges of 12–15 and 16–19 years, a low 8% (4% females, 11% males) completed that amount. ⁸ In addition to being overweight/obese, inadequate physical activity in youths is an independent risk factor for health problems such as cancer and a poor cardiometabolic risk profile (ie, risks for hypertension, dyslipidemia, hyperglycemia, hyperinsulinemia) throughout adolescence and into adulthood. ^9,10 As with overweight and obesity in youths, physical inactivity is an international problem.

In the US, only 29% of pediatricians and family physicians reported regularly screening for an unhealthy BMI in children and adolescents, ¹¹ and only 33% and 23%, respectively, were able to correctly identify physical activity guidelines. ¹² Many physicians indicated a lack of time and their own low self-efficacy in the area as a barrier to addressing their young patients’ weight, nutrition, and physical activity. ¹³ There is high agreement among both medical professionals ¹⁴ and parents ¹⁵ that schools should play a major role in providing physical activity.

Present Inadequacies in Supporting Physical Activity

Youths spend much of their time at school; thus, it is a logical place to address their physical activity needs. However, physical education (PE) has generally been an inadequate solution. ^6,16 As an exemplar of other findings, ^6,17 and even within a school system formally recognized for excellence in health promotion programming, students attained a mean of only 8 minutes (out of a 60-minute lesson) of moderate-to-vigorous physical activity during PE classes (grades 4–8). ¹⁸ Based on this, even if PE classes were to be held each school day (which is extremely rare), ¹⁹ only 13% of the weekly physical activity amounts required for health benefits would be achieved. Congruent with such findings, but in opposition to other suggestions, ²⁰ some posit that health promotion is not a central concern of physical educators ²¹ and many of their foci (eg, elucidations of sport skills) are of an inactive nature leading to minimal impacts on physical activity requirements and health. ²²

Because of this reality, programming either before or after school has been applied and tested to supplement PE and associations between physical activity and students’ health. However, minimal overall impacts were found in a review of such interventions. ²³ A need to develop treatment to better incorporate behavioral theory, process evaluation, and assessments of mediators of effects, particularly as such programs often have multiple components and targets (eg, nutrition, physical activity, improved body image, healthy BMI), was cited. ²³ In a meta-analysis of 61 interventions focused on physical activity, nutrition, and weight starting in 1980 (ages 2–21 years), 79% of the reviewed programs failed to elicit significant improvements in BMI relative to a control condition. ²⁴ The overall effect was “very weak” (r = 0.04), with elementary school age participants demonstrating the poorest outcomes. Effects were significantly greater in youths with health risks and when psychosocial variables were addressed. ²⁴

Although acknowledging benefits for maximizing moderate-to-vigorous physical activity within school-based settings, it was suggested that supplementing student activity through out-of-school time (eg, weekends, evenings) is imperative to reach the recommended amount of physical activity. ²⁵ This freely chosen physical activity time has sometimes been referred to as “voluntary physical activity” because it is outside the domain of the structure imposed upon children through PE and other programming. ²⁶ Based on the social cognitive theory ²⁷ and self-efficacy theory, ²⁸ it has been proposed that improved perceptions of one’s physical self would be required to increase voluntary physical activity in relatively inactive youths. ²⁹ This might be especially true when physical activity is not inherently reinforced due to participants’ high weight, which leads to fears of social comparison, embarrassment, and physical discomfort. ³⁰ It was suggested that both moderate-to-vigorous physical activity and fostering the psychosocial conditions that promote said voluntary physical activity should be a focal point of future interventions. ^31,32

Defining Emergent Possibilities

Although associations between increased physical activity and a healthier weight in youth who specifically were overweight or obese have been found, ^33,34 such treatments had minimal overall effects and, with few exceptions, their mechanisms have not been well-investigated through accepted behavioral theory. ^23,24,35,36 For example, increased feelings of the physical self and competence in physical pursuits (ie, self-efficacy) could lead to greater engagement in physical activity. This premise is supported by tenets of the self-efficacy theory. ²⁸ Baker and Brownell ³⁷ suggested that, in addition to self-efficacy, improvements in self-esteem, body image, coping with challenges (eg, self-regulation), and mood are associated with both increased physical activity and weight control. Such a focus on interactions between psychological/cognitive, behavioral, and environmental/situational factors is congruent with social cognitive theory ²⁷ and has been the basis for successful exercise support/weight control intervention in adults. ^38–40 However, although this is contrary to suggestions, ⁴¹ the current state of analyses related to physical activity and obesity prevention treatments in youth have generally been limited to findings of simple bivariate associations between a treatment and an outcome. ^23,24,42 To provide the necessary means for extending (or even adequately understanding) the impacts of treatment in youths, more improved theory-based testing of malleable mediators and moderators, especially within the psychosocial domain, is required.

Research Aims

Considering that PE is lacking in terms of facilitating enough moderate-to-vigorous physical activity to promote a healthy weight in youths, and theory-based development and analyses of effects of supplementary programming are needed, the following research aims were established: 1) develop and evaluate theory-based curricula to increase physical activity and promote a healthy weight (eg, during afterschool-based programming); 2) test for its effects on physical activity (both within and beyond the treatment settings), BMI, and their putative theory-based correlates; 3) refine methodologies based on findings to maximize their efficiency and impacts; 4) evaluate processes and outcomes especially in high-risk settings/populations (eg, bariatric surgery or high diabetes risk); and 5) assess any augmented effects associated with technology-related program supplementation.

Thus, we report here on an 18-year field-based program of inquiry (2004–2022) intended to address the previously mentioned aims and fill research gaps in a manner that will inform intervention architectures for large-scale improvements in youth physical activity and overweight/obesity control. Although not always carried out sequentially, for ease of interpretation, the remainder of this article chronicles that research program via progressive “research-to-practice tasks.”

Systematic Inquiry

Research-to-Practice Task #1: Addressing Correlates of Behavior Change

Driven by social cognitive theory and self-efficacy theory ^27,28 ; research suggesting that physical activity behaviors can be increased through improvements in the physical self, self-efficacy, and self-management ^37,43,44 ; and our cognitive-behavioral exercise adherence/weight-management protocol for adults, ^38,39 initial research evaluated effects of our structured afterschool curriculum for youths aged 5–12 years entitled Youth Fit For Life. Along with inclusion of moderate-to-vigorous cardiovascular exercises each day that incorporated activities focused on personal progress rather than participant-to-participant competition, the 3 day per week, 45 minutes per session curriculum also featured 2 day per week integrating resistance bands (ie, strength training) and a behavioral skills instruction component once per week. ^26,45,46 The curriculum lasted 12 weeks and was repeated during the Fall and Spring with a 12:1 participant-to-instructor ratio. The 45-minute duration was due to administratively imposed requirements for academic time (eg, homework help) during afterschool care.

The novel behavioral skills component included age-appropriate training in self-management/self-regulatory skills such as distal and proximal goal setting, individualized progress tracking, facilitating self-talk/cognitive restructuring, relapse prevention, and identification of appealing physical activities and recruitment of social supports for those activities. The behavioral skills chosen for this curriculum were selected from taxonomies of self-regulatory techniques for behavioral interventions based on the principles of social cognitive theory. ^47,48 Associated processes within the treatment curriculum facilitated ongoing instruction, rehearsal, and guidance for personalized tailoring of the self-regulatory skills.

Because measuring the impact of the psychosocial factors of interest on 5–7-year-olds was found to lack adequate validity, such analyses were limited to ages 8 years and above. Substantial improvements in physical self-concept, general self, physical appearance, exercise barriers, self-efficacy, and overall mood were found compared to control conditions, ^{26,45,49–60} as were improvements in the mood dimensions of anxiety, depression, fatigue, and vigor. ^{49–51,54–56,60} Because an acceptable instrument had not been identified, we adapted a scale intended for adults ⁶¹ and validated it to measure exercise barrier self-efficacy in children (see Table 1) ⁴⁵ based on suggestions from Bandura. ⁶²

Table 1:

Exercise Barriers Self-Efficacy Scale for Children

The sentences below are common reasons preventing people from exercising. Using the 1-5 scale below, please write (to the left of each reason) how confident you are that you could exercise if the following occur.
Not at all confident		Somewhat confident		Definitely confident
1	2	3	4	5
I am sure I can exercise 3 or more days per week even if:
_____ The weather was bad (very hot, rainy, very cold).
_____ I was bored by the exercise program or activity.
_____ I felt physically uncomfortable while exercising.
_____ I had to exercise alone.
_____ Exercise was not fun.
_____ It was difficult to get to the planned exercise location.
_____ I didn’t like the activity I was involved in.
_____ I had a lot of homework.
_____ I was nervous being around other people.
_____ An instructor did not offer me any encouragement.

Although substantial mood improvements were consistent, their effect sizes were notably smaller than in our research on physical activity in adults. ^63,64 Adaptations of the previously mentioned treatment methodologies for youths ages 10–14 years ⁶⁵ and 12–17 years, ⁶⁰ who were overweight/obese and had at least one additional risk factor for type 2 diabetes, included a focused nutrition education component. Substantial improvements in physical self-concept, general self, and mood were also found; however, improvements in exercise barrier self-efficacy failed to reach statistical significance in the obese participants. ⁶⁵ To address the need for increased gains in self-efficacy, more attention was given to proximal goal setting and incremental progress feedback facilitated by the newly learned self-regulatory skills so that feelings of competence would be amplified. Although it was posited that the minimal improvements in self-efficacy could be an artifact of measurement timing (high self-efficacy at the baseline decreasing in the face of barriers only to then return to a near baseline level; ie, a “U”-shaped pattern viewed as simply little pre- to post-treatment change), post-publication inspection of the data did not support this theory.

Research-to-Practice Task #2: Effects of Psychosocial Changes on Targeted Outcomes

Further analyses suggested that voluntary physical activity consistently increased after the treatment-associated improvements in physical self-concept, general self, physical appearance, exercise barrier self-efficacy, ^{26,52,54–57,59} and mood. ⁵⁰ Those effects were heightened when participants were initially participating at a low activity level, ^59,66 where the overall explained variance in physical activity change was high at R ² = 0.61. ⁵⁹ Our additional research also supported the premise that increases in physical self-concept, general self, and physical appearance were strongly associated with increased exercise barrier self-efficacy (both statistically and conceptually) ⁶⁵ and, as identified in similar research with adults, ⁶⁷ were related to an environment emphasizing personal mastery ^26,45 and feelings of ability empowered through the treatment’s prioritization of self-regulation to navigate exercise-related challenges. Thus, the importance of the self-regulation component for future treatment extensions was reinforced.

Through a review of these studies, it was determined that the strong intercorrelations between the measures of physical self-concept, general self, physical appearance – and exercise barrier self-efficacy – indicated that these correlations, along with their gain scores, could be consolidated and represented by the construct of self-efficacy in future research. Additionally, self-efficacy was found to be strongly associated with a transtheoretical model stage (eg, preparation, action, maintenance), ⁶⁸ and, as predicted, that stage was associated with voluntary physical activity. ⁵⁸ These findings were remarkably consistent with corresponding research on adults ⁶¹ and have implications for attuning intervention by participants’ transtheoretical model stage if/when logistics permit.

Regarding changes in BMI, the Youth Fit For Life protocol, which had been administered primarily during afterschool care but also before school ⁶⁹ and during PE ^54,58 was associated with substantially fewer increases than either control conditions or predicted changes based on normative values associated with maturation. ^{45,54,55,57,59,69–71} In some cases, body fat percentage was also accounted for and improved proportionately. The greatest effects of this protocol were when participants were either overweight or obese. As an example, one of the strongest impacts on BMI was found in a sample of Mexican-American children ages 5–11 years old where the mean baseline percentile for BMI was high at 97%. ⁶⁹ A meta-analysis on the effects of the Youth Fit For Life treatment on BMI change included 16 studies. ⁷² When contrasted with a meta-analysis that was similarly conducted on youths of comparable ages (45 obesity prevention treatments), ²⁴ the aggregated effect size (calculated as r) for Youth Fit For Life was 7 times greater (95% confidence interval [0.02, 0.12]) than that report’s overall effect (95% confidence interval [-0.02, 0.03]). ²⁴ Table 2 denotes comparative data on effect sizes based on moderator variables. Notably, treatment effects in both meta-analyses did not significantly differ when treatment administration was via PE professionals or counselors formerly untrained in PE methods. ^24,72

Table 2:

Contrasts of moderator-based effect sizes for BMI change (r) within meta-analyses of 5- to 12-year-olds

Moderator	Youth Fit For Life 72	Stice et al 24
	r [95% CI]	r [95% CI]
Physical activity mandated	0.07 [0.02, 0.12]	0.01 [-0.01, 0.04]
Intervention length 8–16 weeks	0.07 [0.02, 0.12]	0.02 [-0.03, 0.07]
Girl-only participants	0.07 [0.02, 0.12]	0.11 [0.00, 0.23]
Mean age ≥ 5.0 to 7.9 years	0.05 [0.00, 0.10]	0.07 [0.03, 0.11]
Mean age ≥ 8.0 to 12.0 years	0.08 [0.03, 0.13]	0.00 [-0.02, 0.03]
Majority White	0.05 [-0.02, 0.11]	0.01 [-0.02, 0.04]
Majority Black and/or Hispanic	0.08 [0.04, 0.13]	0.04 [0.01, 0.07]
Administration as physical education (PE)	0.04 [-0.07, 0.16]	0.02 [-0.04, 0.09]

Changes in physical activity and cardiorespiratory fitness were inversely related to changes in BMI/body composition, ^59,69 as was a change in fruit/vegetable intake (a marker of the health of the overall diet). ^55,57 Associations between increases in physical activity and healthy eating behaviors, even when eating was not a program focus, have previously been found in adults ⁷³ and were recently investigated under the purview of “coaction” (ie, a change in one behavior results in a proportional change in another behavior). ^74,75 Mediation of the coaction effect was suggested to be caused by increased self-efficacy, ⁷⁶ a focus of the present youth-based protocols.

Because increased inactivity and being overweight/obese was also a concern for preschool children (ie, children ≤ 5 years), ^1,3 we adapted and applied theory-based cognitive-behavioral methodologies similar to Youth Fit For Life for children ages 3–5 years. The structured protocol, entitled Start For Life, was administered by preschool teachers and their assistants who were nearly all previously untrained in exercise methods beyond general safety procedures. ^77–80 The goal was again to maximize moderate-to-vigorous physical activity and control the number of children who were overweight/obese. In this protocol, exercise was within an allotted 30 minutes per day period, 5 days per week. The protocol also sought to foster physical activity increases beyond the structured program through age-appropriate, theoretically driven behavioral skills training for the young children. These behavioral skills included: goal setting, progress feedback (supported by an “achievement chart” where stickers annotated goal progress), productive self-talk, and mood regulation through instruction in deep breathing, stretching, and basic yoga poses. This behavioral skills component was interspersed throughout the physical activities focusing on gross motor skills and varied in intensity throughout the sessions. Individually tailored statements of encouragement from teachers were intended to increase participants’ task self-efficacy.

Unfortunately, adequate assessment of changes in psychosocial factors were deemed impossible given the measurement challenges for this age group in a preschool setting. However, substantial 8-week increases in accelerometer-based measurements of vigorous and moderate-to-vigorous physical activities throughout the school day were found relative to the usual care condition. ^77,78 Effects were greatest in those in a lower BMI percentile. ⁷⁸ In research during the full 9-month school year, similar physical activity patterns persisted with reductions in BMI of d-values of 0.24 and 0.30 for participants who were overweight and obese, respectively. ⁷⁹ Using an accepted algorithm, ⁸¹ it was found that 87% of the identified change in the weight gain slope was attributable to the alterations in physical activity associated with the Start For Life treatment over 9 months. ⁸⁰ The protocol was not, however, associated with a substantial reduction in sedentary time throughout the school day, which minimized opportunities to accumulate the health-benefit requirement of 300 minutes of moderate-to-vigorous physical activity per week. The lack of autonomy in children aged 3–5 suggested that extensions of this research should focus on additional segments of the preschool day (eg, effects on teacher behaviors to induce more physical activity throughout the school day) and parents (to expand their child’s active vs sedentary time outside of preschool). ⁷⁹ Regular parental meetings were thus added with this focus in mind, but their effects are untested.

In a variation of these previously mentioned emphases on theory-based correlates of increased physical activity during ninth grade health education, 6 40-minute classes focused upon physical activity-related goal setting, anxiety control, self-regulation to overcome barriers, feelings of incremental success through progress tracking, and promotion of a healthy self-concept were developed and evaluated. Although positive effects on exercise self-efficacy, mood, body image, physical self-concept, and moderate-to-vigorous physical activity over 6 weeks were minimal, ⁸² there was a significant association between improvements in mood and increased physical activity with the strongest association occurring initially in the least physically active participants. That association was mediated by changes in body satisfaction for girls but not for boys. ⁸³ This supported an important area of attention for females of the adolescent age group regarding their eating and other health behaviors. ^84,85 Although the intervention dosage appeared too minimal to see clinically meaningful effects, the research suggested that, as proposed by Baker and Brownell ³⁷ and social cognitive theory, ²⁷ mood and body image improvement and addressing barriers are useful targets for classroom work seeking to increase physical activity and its psychosocial correlates in adolescents.

Research-to-Practice Task #3: Extending Treatment Foci and Effects

Based on the the findings concerning the most salient (malleable) psychosocial predictors of voluntary physical activity in youth, feedback from those who administered the elementary afterschool protocol, and our research program on exercise and behavioral changes in adults, ⁸⁶ the Youth Fit For Life treatment was substantially revised over a 1.5 year period (and given the slightly different title of “Youth Fit 4 Life” [substitution of the numeral “4”]). The group of contributors in that revision included those in the disciplines of pediatric medicine (MD), behavioral health psychology (PhD), exercise physiology (MS), health education (MEd), health administration (MS), and nutrition science (MS). Our findings on coaction in adults, ⁷⁶ and more preliminary findings in youth, ^55,57 influenced our attempts to use an emphasis on enhanced behavioral skills to generalize changes in physical activity behaviors to other health behaviors (eg, healthy eating and proper hydration) and better control over their weight and obesity status. It was, however, also acknowledged that the prevention/management of weight and obesity in children should differ from such efforts in adults. ⁸⁷ For example, in children, energy expenditures associated with increased physical activity/exercise appears to account for a greater portion of reduction in overweight/obese participants than that of adults (which is mostly from dietary-based caloric reductions). ^40,88,89 This justified a strong concentration on maximizing moderate-to-vigorous physical activity both within the Youth Fit 4 Life protocol and beyond the school setting and, as articulated within social cognitive theory, ^27,90 facilitation of control over social and environmental barriers. ⁸⁷ Also, it should be noted that Youth Fit 4 Life was simultaneously applied to groups of children (increased to a 15:1 participant-to-instructor ratio) of a healthy and unhealthy BMI. Thus, targeting pointed dietary alteration (compared to general increases in healthy behaviors) would have required specialized training of its instructors that was not considered consistent with its large-scale, field-based application intentions.

Therefore, the protocol was extended from 3 to 4 days per week, but it remained 45 minutes per session. It included 30 minutes of moderate-to-vigorous cardiovascular physical activity after a 5-minute warm up, some of which was intended to reinforce the extended training in the self-management of behavioral changes (ie, “content reinforcement” activities) that were now doubled to 2 days per week. The presented self-regulatory skills were again selected from taxonomies that fit under the auspices of social cognitive theory. ^47,48 However, the extended time frame now allowed more thorough instruction and more time for practice under hypothetical situations that included common barriers (eg, when the activity was boring or uncomfortable). Health (including general nutrition) topics were included on alternate days supported by child-friendly posters. Additionally, intermittent body weight resistance exercises replaced the use of resistance bands to maximize participants’ time in moderate-to-vigorous cardiovascular activity. There were also now separate curricula for ages 5–8 and 9–12 years, each with 96 unique lessons (4 sessions per week for 24 weeks).

The 3 primary targets for psychosocial change, although still guided by social cognitive and self-efficacy theories, ^27,28 were now clearly self-regulation, self-efficacy, and mood (Figure 1). The increased emphasis on instruction in self-regulation skills countering barriers and leading to improved self-efficacy also drew on tenets of self-regulation theory ⁹¹ and our research with adult participants. ⁸⁹ Accelerometer data on 9–12-year-old participants demonstrated substantially greater improvements in vigorous and moderate-to-vigorous physical activity in the new (Youth Fit 4 Life) vs original (Youth Fit For Life) protocol. ⁴⁶ In a 9-month study with a mean participant age of 7 years, the superior improvements in BMI in Youth Fit 4 Life vs a control condition of usual care was mediated by a change in exercise self-efficacy. ⁹² Effects on the fitness measures were most pronounced in participants who were overweight and obese.

Figure 1:

Psychosocial predictors of increased physical activity as treatment targets.

In multiple regression analyses, impacts of improvements in self-regulation, self-efficacy, and mood, when considered together, more strongly supported the prediction of increased physical activity and reduced BMI ^93–95 than through self-efficacy change alone. Although changes in each of these 3 treatment-targeted psychosocial variables demonstrated bivariate relationships with improvements in both physical activity and BMI, which is consistent with related research on adults, ⁸⁹ increases in the usage of self-regulatory skills addressed in the curriculum explained the majority of the variances. ^74,93–96 Also, in alignment with research using adult participants, ³⁸ there was evidence that a change in self-efficacy became increasing relevant as intervention duration progressed. ⁹⁴ In predicting increased physical activity, overall changes in self-regulation, self-efficacy, and mood explained 23–39% of the variance, ^95–97 and, in one study, the 300 minutes per week of out-of-school physical activity increased from 41% to 71% of participants in the Youth Fit 4 Life group. ⁹⁶ The previous issue regarding the need to increase self-efficacy in youths with obesity also appeared to be rectified through enhanced attention on feelings of competence related to the use of self-regulation to overcome barriers. ⁹⁵ There were substantial associations between increased physical activity and reduced BMI, ^95,97 and it was estimated that 39% of the weight lost was directly attributed to the physical activity changes in a sample of 8–11-year-olds at or above their 90th percentile for BMI. ⁹⁵ Substantial increases in cardiorespiratory function associated with the program, but not the strength changes, similarly predicted BMI change in both boys and girls of ages 9–12 years. ⁹³

Although mood was already consistently improved within Youth Fit 4 Life conditions, ^93–97 the addition of yoga was tested for increased effects. ⁹⁸ Although findings were preliminary due to a small sample size, improvement in the overweight/obese participants (d-values of 0.52 and 0.67 over 3 and 9 months, respectively) appeared greater than the small-to-moderate negative effects on overall mood (an aggregate measure of anxiety, dejection, fatigue, anger, confusion, and energy level) found in applications of each of our previously tested afterschool protocols. The change in self-efficacy was a significant mediator of the relationship between group membership and mood change. ⁹⁸ Because reciprocal associations were also found between self-efficacy and mood changes, ⁹⁸ it was posited that the self-regulation properties of yoga positively affected participants’ perceived physical abilities, mood, and their interrelations.

Research-to-Practice Task #4: Carryover Effects on Eating in High-BMI Youths

Although our research goal of increasing physical activity and controlling overweight and obesity in youths has large-scale implications consisting of simultaneous group-based applications in those with both healthy and unhealthy BMIs, we also tested these methods on adolescents with “extreme” or “severe” obesity (ie,≥120% of the respective 95th percentile for BMI) ⁹⁹ who were considering (along with their parents/caregivers) bariatric surgery within pediatric medical venues. ^100,101 Along with higher energy intakes and a poorer cardiometabolic risk profile than their overweight/obese counterparts, both steps taken per day and moderate-to-vigorous physical activity had also been shown to be substantially lower in that highly at-risk population. ¹⁰² Findings indicated that targeted improvements in self-regulation, self-efficacy, and mood predicted the increased physical activity. ^100,101 Although only self-regulation and self-efficacy changes were substantial independent predictors, mood and physical activity changes demonstrated a reciprocal relationship, and depression score significantly mediated the relationship between self-efficacy and change in physical activity change in one study. ¹⁰⁰ In our other study with adolescents with extreme obesity, the change in self-regulation was the most salient predictor of increases in physical activity with a notable 52% of the variances accounted for through combined changes in self-regulation, self-efficacy, and mood. ¹⁰¹ Although impacts on BMI were negligible in both studies, and further research is required to evaluate carryover effects on eating behaviors in that subgroup, continued increases in BMI were reduced and 17% of the variances was explained through the 3 targeted psychological factors. Positive implications for the present protocol were also evidenced by the finding that the relationship between physical activity and self-regulation was impacted by body esteem, social life, physical comfort, and family relations; these are variables that were previously considered to be strong correlates of weight in adolescents with severe obesity. ¹⁰³

Additional Effects of Technology

Because youths display a considerable comfort level with technology and are frequent consumers of virtual reality–enhanced modalities, ^104,105 we tested these modalities for their additional effects with our aforementioned protocols in elementary afterschool settings. In one study, a video-based interactive group exercise system (HOPSports, Inc., Las Vegas, NV) was employed for the 2 sessions per week when Youth Fit For Life activities were not scheduled. ⁷¹ This contrasted with low structured activities completed during the corresponding times under the supervision of existing afterschool counselors. Although there were significant overall improvements in measures of cardiorespiratory fitness, strength, and BMI over 12 weeks (d-values for BMI change were 0.10 vs 0.07, respectively, and d-values were 0.15 vs 0.17, respectively, for participants that were overweight/obese), there was no significant group × time difference in any of those gains. ⁷¹ Thus, significant additional effects associated with the video system were not detected.

By employing tenets of the self-determination theory (where the autonomous choice to be physically active is a key consideration) ¹⁰⁶ and social cognitive theory (where the benefits of vicariously demonstrated physical activity and increases in task self-efficacy are central), ²⁷ the feasibility of a modality where a kiosk-administered virtual reality–driven pet (dog) that increases its capability to perform tricks/tasks based on a participant’s accelerometer-tracked physical activity outputs was supported using a group of 6–10-year-olds. ^107,108 Inclusions also facilitated personal goal setting, goal-based physical activity feedback, and the real-time transfer of electronic data of a child’s physical activities to parents/caregivers (in the hopes that support emanating from such data would increase outputs). Although related studies ^109,110 indicated that additional research is required to understand and effectively shape such parental support efforts, it was interpreted that the self-determination theory-based needs for autonomy, competence, and relatedness ¹⁰⁶ were addressed.

Although preliminary research demonstrated that the children’s amount of interfacing with the virtual agent was considerable at over 18 days of access, ¹⁰⁸ translation of that into moderate-to-vigorous physical activity (which could be interpreted to be voluntary physical activity due to its discretionary nature) beyond what was found through its research-associated pairing with Youth Fit 4 Life requires further investigation. It will be of particular importance to determine if the virtual dog’s coupling with Youth Fit 4 Life elicits additional or increased psychosocial changes (eg, competence/self-efficacy, goal striving/self-regulation) that leads to any further increases in physical activity outputs and/or other health benefits. It will also be important to determine if the parental support component augments the targeted autonomous decision making and its associated effects.

Summary

This article reviewed an 18-year applied research program based on accepted behavioral theory with the aims of: 1) empowering effective supplementation of school PE for increased physical activity in youths and promotion of healthy weight/BMI; 2) evaluating theory-driven psychological correlates of behavioral changes to develop and refine interventions to maximize health-promotion effects; 3) assessing emerging cognitive-behavioral treatment adaptations that cross age ranges and various health risks in youths; and 4) evaluating program adjuncts via technology. More specifically, the research program’s associated studies tested theory- and research-based hypotheses in the development and extension of standardized protocols intended for large-scale community-based applications in very young children through adolescents. The appropriateness of a systematic investigation in this area was presumed through findings of reduced amounts of physical activity currently observed in youths, ^5,8 the strong association of low physical activity outputs with high rates of overweight and obesity, ^5,8 and evidence that traditional PE is not presently positioned to successfully impact the previously mentioned health risks. ^21,22 Although the article was not intended to be a comprehensive review of the related literature, it described an evolution of research that encompassed much of the relevant scientific examination. It also extended typically used analytic approaches of simple associations between treatment and outcome in favor of the suggested ¹¹¹ assessment of mediators and moderators that could meaningfully shape and reshape treatment components via longitudinal testing.

The chronology of the research program was expressed through specified tasks. In research-to-practice task 1, which began in 2003 with reporting starting in 2004, our research group developed a treatment intended for elementary afterschool care. Its grounding in social cognitive and self-efficacy theories, ^27,28 and adaptations based on relationships between physical activity, eating behaviors, and healthy weight, ³⁷ fostered longitudinal assessments of changes in exercise behaviors; measures of fitness and body composition; and perceptions of physical abilities, the physical self, and mood. In attempts to maximize physical activity both within and beyond the program, cardiovascular and strength components emphasized participants’ goal progress and behavioral skill development while reducing participant-to-participant competition to minimize feelings of threat and maximize self-efficacy. This was especially helpful in the most deconditioned children. Through 2014, task 2 assessed changes associated with the treatment regarding its effects on outcomes and correlates of behavioral improvements. Attention was placed on the carryover of psychosocial changes and increases in physical activity within the program to improvements beyond the program itself and its overall effects on high BMI. Consistent advances were found when measuring physical and general self-concept, physical appearance, and mood. However, subsequent analyses using improved instrumentation determined that the targeted psychosocial variables for behavioral changes should be consolidated to self-regulation, self-efficacy, and mood. The effect sizes for both physical activity and body composition/weight improvements were uniformly greatest in the least active participants and those with the highest BMI percentiles. There was also evidence of coaction between improvements in physical activity and healthy eating behaviors.

Within task 3 and based on the previous findings, testing began in 2015 on our substantially revised and extended curriculum directed at afterschool care (Youth Fit 4 Life). The curriculum’s effects on physical activity were superior to the previous treatment iteration. ⁴⁶ Further emphases were placed on developing self-management/self-regulatory skills because increases in these skills were demonstrated to be the strongest predictor of raised levels of physical activity. ^74,93–96 Across age ranges in Youth Fit 4 Life (5–12 years) and Start For Life (3–5 years) applications, increases in moderate-to-vigorous physical activity were shown to be an even stronger predictor of a healthier weight than in adults, with the greatest benefits found in participants with BMI percentiles indicating initial overweight and obesity. There continued to be strong correlations between the effects of improvements in self-regulation, self-efficacy, and mood and behavioral changes, which became the distinct focus of each of the treatments’ physical and educational curricula. Within task 4, processes that addressed youths with multiple risk factors for diabetes were adapted and extended to adolescent candidates for bariatric surgery – all with extreme/severe obesity. For this highly at-risk faction of participants, it was found that the relationship between self-regulation and physical activity was affected by psychosocial variables including body esteem, ¹⁰¹ which might require further treatment adaptations for such subgroups. Although technology could be a promising avenue for promoting physical activity in youths, ^104,105 its supplementary effects explored within the present research program were minimal via the incorporation of interactive virtual PE classes. ⁷¹ The viability of a newly developed virtual reality pet dog whose capabilities increased with their (virtual) participant/master’s increased physical activity requires more complete testing. ¹⁰⁸

Conclusion

The importance of finding a solution to increases in inactivity and overweight/obesity in youths is great considering the strong evidence of their carryover into adulthood and the lifetime of health risks and associated medical treatments. ¹¹² Although medical professionals should increasingly address and advocate for adequate physical activity and a healthy weight in their patients, they require evidence-based solutions away from their medical settings to ensure adequate day-to-day processes that support continuity of positive behavioral changes. There are also ancillary benefits to increasing physical activity in youths that go beyond their proven physical and mental health benefits. For example, increased physical activity (possibly through its self-regulatory properties) ¹¹³ is associated with improved cognitive/academic performance. ¹¹⁴ Given that, it is hoped that as the overall benefits of exercise and physical activity become better realized by school administrators and society in general, efforts to meaningfully promote such within the school day are advanced. Until that time, however, effective supplementation of existing PE methods will be needed. Therefore, interventions that have strong theoretical and evidence bases but are applicable through straightforwardly administered protocols in a large-scale manner by community-based organizations (eg, YMCAs and community health centers), ¹¹⁵ will be greatly needed for increasingly sedentary youths. ^116,117 Although progress toward these ends was realized through the 18-year research program overviewed here (which advocate novel emphases on participants’ development of self-regulatory skills, feelings of competence, and emotional well-being), continued applied research from a cross-disciplinary perspective will be essential.