An Intervention to Prevent Weight Gain and Unhealthy Behaviors in Children From Economically Disadvantaged Circumstances
Phase: NA
Conditions: Obesity
Sponsor: University of South Carolina

Title: Preventing Weight Gain and Unhealthy Behaviors in Children 
08/08/2019 

Rigor and Transparency. The proposed study is designed to rigorously evaluate the effect of providing access 
to structured programs during the summer on children’s unhealthy weight gain, fitness loss, and the obesogenic 
behaviors that underlie these effects. Specific examples of the rigor of this study include randomizing children 
following baseline measurement, using measures shown to produce valid and reliable data in the study population, 
completion of a power analysis, appropriate statistical analyses, properly controlled design, and blinding staff handling 
the data to study condition. These methods will allow for the proposed study to produce robust and unbiased results.  
D1. Theoretical/Conceptual Framework - Structured Days Hypothesis. This study hypothesizes that 
summer camps will provide structure during the summer that will reduce children’s obesogenic behaviors. 
Mechanisms driving reduced obesogenic behaviors on structured days are detailed in Figure D1 below. 
D2. Hypotheses.  
Aim 1 (Primary): It is hypothesized that A) children randomized to attend the summer day camp will 
experience minimal gain in zBMI and loss of fitness during the summer that they receive summer camp 
access; B) children will experience accelerated weight gain and fitness loss during the summer they are 
randomized to not receive summer camp access and that C) all children will experience similar weight loss and 
fitness gain during the school year due to the restrictive, compulsory, and regulatory components of school. 
Aim 2 (Secondary): It is hypothesized that A) children randomized to attend the camp will engage in 
fewer obesogenic behaviors during the summer that they attend the camp than their peers during the summer 
they do not attend camp, and that B) all children will engage in fewer and similar levels of obesogenic 
behaviors during the school year due to the restrictive, compulsory, and regulatory components of school. 
Aim 3 (Exploratory): It is of interest to explore: A) if children randomized to attend the camp will 
experience increases in self-regulation while their peers who do not attend the camp will experience decreases 
in self-regulation, and if B) self-regulation at the beginning of summer will moderate unhealthy changes in 
weight and fitness at the end of the summer for those children who do not attend the summer camp. 
D3. Study Design. The study will be a randomized controlled trial. To distribute costs over years, the study will 
recruit two cohorts of 1st and 3rd grade students. The first cohort will be recruited in Y01 and the second will be 
recruited in Y02. Following baseline data collection, children in each cohort will be randomly assigned to either 
the treatment or control. The sample of students recruited in the 1st grade will be observed during the summer 
after their 1st grade year and the school year when they are in the 2nd grade. Students recruited from the 3rd 
grade will be observed in the summer following their 3rd grade year and the school year during 4th grade.  
D4. Study Population and Recruitment. Procedures for sampling children are detailed in Clin-Trls Section 2, 
Recruitment and Retention Plan. Briefly, the Recreation Commission operates 11 summer day camps located 
Figure D1. Structured Days Hypothesis Conceptual Model 
Abbreviations—physical activity (PA), sedentary time (ST), body mass index (BMI), cardiorepiratory fitness (CRF), self-regulation (SR) 
Morning routine can include active 
commute to school and/or before 
school program 
Compulsory physical activity 
(PA) opportunities through 
transitions, PE, recess, 
classroom activity breaks
~5:30-6:30AM
Child discretionary wake time
~9:00-10:00AM
School day contains various restrictive, 
regulated and compulsory components
~7:30AM – SCHOOL HOURS
PA
Diet
Regulated calorically, 
specified times to eat, 
and nutritionally 
balanced 
ST
Restricted access to screen 
time (ST) during school hours
PA
Diet
ST
~7:00PM
After school affords active 
commute home and/or attend 
structured after-school programs
Evening contains pre-bed routine 
including eating dinner, doing 
homework and limited ST
~9:00PM
Early Bed time in 
preparation for 
school
Less regulation of what and when 
children eat affords opportunities for 
excess snacking between meals on 
calorie-dense foods 
~11:00 PM – 12:00 AM
Later bed time displaces sleep time 
with sedentary or ST activities and 
opportunities to snack
Lack of compulsory components to the 
day and with less restriction to the 
environment children are afforded open-
ended access to screen time
~2:30PM – AFTER SCHOOL
Children have more freedom 
to  spend their time how they 
like choosing sedentary 
pursuits over physical activity
BMI
CRF
Wake
Wake
12 AM
12 PM
12 AM
+
Co-occurring behaviors 
Displacement of behavior
Sleep
Consistent wake time dictated 
by structured morning in 
preparation for school
Sleep
Consistent bed time as 
part of rules set by 
parents on school nights
Sleep
More freedoms around wake 
time displaces time where 
physical activity occurs
School
Summer
Increase behavior
Decrease behavior
Positive Influence
Negative Influence
Key:
+
SR

at parks. Each camp  serves ~100 children every summer. To draw a sample of children, 5 summer camps that 
operate in the catchment area of elementary schools where ≥90% (range = 90%, 100%) of children enrolled 
are eligible for free and reduced lunch have been identified. A total of 2,333 children (49% female) attend these 
schools. Children attending the identified schools will be stratified by gender and grade level. In Y01 and Y02, 
40 (i.e.,80 total) randomly identified children will be invited to participate in the study.  
D5. Intervention to be Tested. A detailed description of the intervention to be tested can be found in Clin-Trls 
Section 4, Narrative Study Description and Interventions. Briefly, children in the study will be randomly 
identified to take part in the Voucher Program. During the summer, children in the Voucher Program will 
receive a voucher that covers enrollment fees associated with accessing a day camp operated at a park near 
their school. The total value of the voucher for a single child for an 8-week summer will be $880 ($110 per 
week). This fee covers all operating expenses plus transportation to and from the camp. The summer day 
camps (defined in Section A5) will be existing summer day camps operated by the Recreation Commission. 
The summer day camps provide indoor and outdoor opportunities for children to be physically active each day, 
provide enrichment and academic programming, as well as breakfast, lunch, and snacks. Importantly, these 
camps are enrolled in the USDA Summer Food Service Program. Thus, all meals adhere to the Summer Food 
Service Program nutrition guidelines. The camps employ 1 staff member for every 12 children and operate 
daily (Mon-Fri) for the entire summer. The camps open at 7am and close at 6 pm daily. Physical activity 
opportunities are scheduled for 3 to 4 hours each day, with the remaining 4 to 5 hours dedicated to enrichment 
or meals/snacks. These camps will operate according to routine practice, with no outside assistance from the 
investigative team. Children randomly assigned to the control group will be enrolled in the same schools as 
those randomized to receive the Voucher Program. The comparison/control group will not receive a voucher to 
attend a summer camp. It is possible that children serving in the control/comparison condition may elect to 
voluntarily participate in a summer program. However, based on enrollment numbers from pilot work (see 
Section C), the limited number of weeks children were enrolled (avg. of 2 weeks), the associated costs of 
enrolling (i.e., $880 per child), and national data indicating that few children from low-income families attend 
summer day camps (see Section A5), it is unlikely that comparison/control children will enroll in a summer day 
camp. Thus, there is a high degree of confidence that the comparison/control group will represent weight and 
fitness outcomes associated with children not attending a summer program. 
Figure D6. Schedule of school year and summer measurements 
Abbreviations—body mass index (BMI), cardiorepiratory fitness (CRF) 
D6. Primary and Secondary Measures. Details for implementation of the measurement plan will be finalized 
in consultation with the CTL Core with respect to training of data collectors, record-keeping procedures, data 
capture procedures, and construct scoring. For a detailed description of the primary, secondary, covariate, 
predictor, and determinant measures see Clin-Trls Section 4, Narrative Study Description and Outcome 
Measures. All measures were selected in consultation with our consultants, the participating school district, and the 
Recreation Commission. The measures selected 1) represent state-of-the-art techniques that are known to produce 
valid and reliable data and 2) minimize burden on the participating families.  
D6.1. Primary Outcomes (Specific Aim 1). All students enrolled in the study will take part in a cardiovascular 
fitness (CRF) test (i.e., PACER)[2-8] and have their height and weight measured by trained research staff using 
standard procedures during a regularly scheduled physical education class. This information will be used to 
compare changes in BMI (translated into age-sex z-scores [zBMI]) and CRF during summer and the school 
year. The tests are valid and reliable and used extensively with the proposed age groups.[59-63] Peak height 
velocity will also be collected as a marker of biological maturation (covariate in statistical models).[1]  
D6.2. Secondary Outcomes (Specific Aim 2). Briefly, physical activity, sedentary behaviors, and sleep will be 
collected using a non-dominant wrist-placed ActiGraph Link for 9-days (common timeframe to collect physical 
May
August
8 Week Camp
School Year
School Year
BMI, CRF, Self Regulation Measurements
Specific Aim 1,3
9-day protocol
Specific Aim 2
BMI, CRF, Self Regulation Measurements
Specific Aim 1,3
9-day protocol
Specific Aim 2
Summer
Control Group
Does not receive summer camp voucher
Intervention Group
Receives summer camp voucher
May
BMI, CRF, Self Regulation Measurements
Specific Aim 1,3
July

activity data).[45, 64-74]  Children’s screen time will be assessed using a parent-proxy report measure 
completed daily for 9 days by the parent with their child. Parents/children will estimate the total amount of time 
(hours and minutes) spent in front of a screen that day (e.g., TV, computer, video-game, smartphone, and 
tablet). [75] Dietary behavior of participants will be estimated using several dietary screeners that have been found 
to be valid and reliable when compared to multiple pass dietary recall.[76-90]  
D6.3. Covariate, Predictor, and Determinant Measures. Participant self regulation will be reported by the 
classroom teacher and parent/guardian of each child prior to and following each summer.[91] Children will also 
complete a similar COMPSCALE – Short Form, an 18-item survey that rates their ability to self-regulate.[92] The 
parent/guardian of each child will also complete a survey that covers rules for bedtime, the home food environment, 
social support for physical activity, and child dietary intake. Survey questions are from established surveys used to 
investigate the influence of parents on the health behaviors of their children. To account for environmental factors 
associated with accelerated weight gain or fitness loss, the obesogenic nature of participating children’s/families’ 
neighborhood environments will be assessed using measures that are consistent with other recent, large-scale 
studies of environmental influences on physical activity and nutrition.[93-96] These measures include walkability 
(e.g., net residential density, intersection density, land use mix, and retail floor area ratio),[97] the number of parks 
(and total park acreage) and the number of public (e.g., municipal community center), non-profit (e.g., YMCA), and 
private (e.g., indoor soccer complex) recreation facilities using publicly-available sources,[93, 94] crime data,[98, 99] 
neighborhood food,[93, 94, 96] and neighborhood-level disadvantage.[100] 
D6.4. Process Implementation Outcomes. Detailed process/implementation data will be captured. 
Specifically, for each child randomized to the Voucher Program or the comparison/control group, information 
regarding their attendance at a summer day camp will be collected. For the Voucher Program group in the 
summer of Y01 and Y02, detailed information will be collected regarding the programmatic offerings occurring 
at the camps, [101-108] and types of foods and beverages served.[109-112]  
D7. Protocol for School and Summer Data Collection. This section describes the protocols for administering the 
FITNESSGRAM assessments, both H&W and PACER, over a 9-day period during the school year and summer. 
During the school year children will run the PACER and have their H&W collected during physical education class 
prior to and following each summer. During this class children will also be provided the activity monitors 
(ActiGraph), and surveys to take home to their parent for completion. For summer, H&W and PACER will not be 
collected (see Figure D6.) but monitors and surveys will be distributed during scheduled family days at the child’s 
elementary school (see below for details). During summer and the school year, the parent/guardian will receive text 
prompts with daily reminders to complete the survey instruments during the 9-day assessment. For the summer, 
parents/guardians and their child will be contacted in one of two ways. The first primary contact will be through a 
day-long (8am-5pm) open house at their child’s school. Parents/guardians of children participating in the study will 
be texted two weeks and one week prior about attending a Saturday open house. Parents/guardians showing up to 
the in-person summer open house will receive $50 when returning the devices and completed survey packet.  
D8. Power Considerations, Statistical Design, and Missing Data. The SDM Core assisted the PI with 
respect to the analytic plan described in this application. The SDM Core will assist the research team with the 
codebook (for raw data and constructs), specification of missing data flagging and procedures, data 
entry/capture, data management, preliminary examination of distributions in preparation for analyses, conduct 
of statistical analyses, and assistance in interpretation of programming output. All analyses will be completed 
by the SDM Core, which will have individuals with extensive expertise in the statistical models required for 
Table D6. Description of Measures for Primary and Secondary Outcomes and Exploratory Variables at the Child Level 
Outcome 
Construct 
Assessment/Tool 
Description/Protocol 
Primary 
BMI z-score (zBMI) 
Height and Weight 
Height (cm), weight (kg) w/out shoes or heavy clothing.  See Section D6.1.for details 
Primary 
Cardiorespiratory Fitness 
PACER 
FITNESSGRAM standardized protocol.  See Section D6.1. for details 
Secondary 
Physical Activity 
Accelerometry 
Physical Activity (ys).  See Section D6.2. for details 
Secondary 
Sedentary Behaviors 
Accelerometry 
Sedentary Activity (9-days). See Section D6.2. for details 
Secondary 
Sleep 
Accelerometry 
Sleep Activity (9-days). See Section  D6.2.for details 
 
 
Daily Diary 
Daily diary (9-days) completed in evening with help of child (when necessary) report of 
bed time and wake – See Appendix for details. 
Secondary 
Dietary Intake 
Child Intake of 
Food/Beverage  
Parent report of child past week food/bev intake. See Section D6.2. 
Exploratory Self-regulation (child report) COMPSCALE – Short 
Form 
The COMPSCALE short form is a 18-item rating scale adapted from the 
COMPSCALE for children to self-report motives and behavioral inclinations that are 
linked to socially competence and self-regulation. See Section D6.3. 
Exploratory Self-regulation (classroom 
teacher and parent report) 
COMPSCALE 
The COMPSCALE is a 35-item rating scale that adults complete about children. It 
measures motives and behavioral inclinations that are linked to socially competent and 
self-regulated children.  See Section D6.3.  

analyzing the data collected in the proposed project.  
D8.1. Power Considerations. Details of the power analysis completed for this study are presented in Clin-Trls 
Section 4, Statistical Power and Design. Based on the hypothesized difference between z-BMI change for 
children who receive and do not receive a voucher (i.e., 0.22 vs. 0.11) this study is sufficiently powered.  
D8.2. Statistical Models. To test the hypothesis in Aim 1 and Aim 2, repeated measures linear and non-linear 
mixed models accounting for repeated measures within children and children within schools will be estimated. 
Group, time, setting (i.e., school vs. summer) and all 2-way and 3-way interactions will be included, with the 
group-x-time-x-setting interaction as the primary contrast of interest. Structural equation models will also 
estimate the mediating pathways of the obesogenic behaviors on zBMI change. 
D8.3. Sex as a Biological Variable. Because girls and boys have been shown to engage in differing levels of 
obesogenic behaviors and to have differing levels of fitness and prevalence of overweight and obesity, all 
models will include sex (i.e., boys vs. girls) and age as covariates. Including sex as a covariate in models will 
preserve the statistical power of the study while allowing for the examination of sex as a biological variable.  
D9. Group Assignment. The unit of randomization will be at the child level. The two conditions will be: 1) 
Intervention - children receiving a voucher for a summer day camp and 2) Control - no summer day camp 
voucher. Children will be randomized (using a random number generator) by stratifying them based on grade 
and gender to ensure equal numbers across the age range and boys and girls in each of the two conditions.  
D10. Timeline. A project timeline is provided in Clin-Trls Section 2, Extended Study Timeline.  
D11. Limitations and Benchmarks of Success. One key to success will be the study retention of 
children/families over time. To address this, the measures have been modified based on piloting with 
comparable individuals and incentives are planned for participation. Another key issue is whether children 
receiving vouchers attend the day camp during the designated summer. Children in the intervention condition 
who fail to attend the camp would obviously not be exposed to the independent variable. However, the 
Recreation Commission has observed that high community demand for summer programming, coupled with 
ease of access because the camp is centrally located, makes attendance likely. Further, camp attendance 
(and lack thereof) will be tracked to explore possible barriers to attendance.  
D12. Transition to R01-level Grant Submission. The knowledge gleaned from this study will be invaluable to 
the development or enhancement of existing systems and interventions that support both the physical (weight 
and fitness), social, and emotional wellbeing children. The study results will provide a foundation for an R01-
level grant submission expanding this line of research on interrupting unhealthy weight gain and fitness loss 
during the summer and continuing to build a foundation for promoting self-regulation to influence both physical 
health and social-emotional development. This study also has the potential to interrupt a long unstructured 
period (i.e., summer) in children from low-income households. This could be crucial for helping these children 
develop self-regulation that could lead to better social, emotional, and behavioral adjustment. The preliminary 
evidence produced by this study will justify an R01-level study to test the Voucher Program in a large-scale 
RCT. Should the Voucher Program prove ineffective, this preliminary study will yield detailed process 
information to inform additional intervention targets for summer programming (e.g., self-regulation). The 
proposed study will be one of the first to measure self-regulation in addition to all four obesogenic behaviors on 
the same children during the school year and summer break. Not all of the behaviors in all the children will 
change in a similar fashion.  This study provides initial evidence to suggest patterns of behavior change in 
groups of children. For instance, activity might substantially decrease in some children without concomitant 
changes in sleep, diet, or screen time. Other children might show change in more than one of these behaviors, 
which might nullify the detrimental changes in the other behaviors or interact in unforeseen ways. Further, this 
study has the potential to produce preliminary data related to the moderating effect of self-regulation on these 
behavioral pathways. Should self-regulation prove critical, the R01 will incorporate more explicit strategies for 
targeting self-regulation and more scientifically rigorous measures of the construct.  Without this evidence, 
efforts to mitigate summer weight gain could be misguided, wasteful of resources by unnecessarily targeting all 
behaviors simultaneously, and less effective than more planned/targeted approaches. Thus, even under 
conditions of null results, it will be possible to develop more effective strategies for reducing unhealthy weight 
gains and fitness loss to test in a rigorous well-powered R01