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Intervention to increase physical activity and healthy eating among under-represented adolescents: GOAL trial protocol
  1. Lorraine B Robbins1,
  2. Jiying Ling1,
  3. Karin A Pfeiffer2,
  4. Jean M Kerver3,
  5. Kenneth Resnicow4,
  6. Harlan McCaffery5,
  7. Aisha Hilliard1,
  8. Logan Hobbs1,
  9. Sheldon Donald1,
  10. Niko Kaciroti5,6
  1. 1College of Nursing, Michigan State University, East Lansing, Michigan, USA
  2. 2Department of Kinesiology, College of Education, Michigan State University, East Lansing, Michigan, USA
  3. 3Department of Epidemiology and Biostatistics, College of Human Medicine, Michigan State University, East Lansing, Michigan, USA
  4. 4School of Public Health, University of Michigan, Ann Arbor, Michigan, USA
  5. 5Department of Pediatrics, Medical School, University of Michigan, Ann Arbor, Michigan, USA
  6. 6Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, MI, USA
  1. Correspondence to Dr Lorraine B Robbins; robbin76{at}


Introduction To reduce obesity-related disparities, reaching economically disadvantaged and/or minority status adolescents to assist them in meeting physical activity (PA) and nutrition recommendations is important. To address the problem, a 16-week intervention called Guys/Girls Opt for Activities for Life (GOAL) was designed. The purpose of this randomised controlled trial is to evaluate any effect of the intervention, compared with a control condition, on improving: (1) adolescents’ % body fat (primary outcome), moderate-to-vigorous PA (MVPA), diet quality and cardiorespiratory fitness from 0 to 4 months; (2) body mass index (BMI), overweight/obesity percentage and quality of life from 0 to 4 months and to 13 months; and (3) perceived social support, self-efficacy and motivation from 0 to 4 months with evaluation of any mediating effect on adolescent PA and diet quality. An exploratory aim is to evaluate any effect of the intervention, compared with the control, on improving parents’/guardians’ home environment, MVPA and diet quality from 0 to 4 months; and BMI from 0 to 4 months and to 13 months.

Methods and analysis Adolescents (fifth to eighth grade) in 14 schools located in underserved urban communities are randomly assigned to the intervention or usual school offerings. One parent per adolescent is enrolled (882 dyads total). Cohort 1 includes four schools (2022–2023). Cohorts 2 and 3 include 5 schools in 2023–2024 and 2024–2025, respectively. The 16-week intervention has three components: (1) after-school GOAL club for adolescents to engage in PA and healthy eating/cooking activities; (2) three parent–adolescent meetings to empower parents to assist adolescents; and (3) GOAL social networking website for parents to share how they helped their adolescent.

Ethics and dissemination The Michigan State University Biomedical Institutional Review Board provided ethical approval for the study. Findings will be shared via the trial registration database, peer-reviewed publications, conferences and community-oriented strategies.

Trial registration number NCT04213014.

  • Adolescents
  • Primary Prevention

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  • Guys/Girls Opt for Activities for Life (GOAL) is a multi-component intervention that includes a novel approach for empowering parents via social networking to assist their adolescents in eating healthy and attaining adequate physical activity (PA) to achieve or maintain a healthy weight.

  • GOAL fosters a synergistic intervention effect on at-risk, under-represented adolescents’ PA and diet quality by simultaneous intervening with adolescents at school and their parents at home.

  • Challenges include enrolling and engaging an adequate number of predominately minority adolescents and parents from underserved urban communities.

  • A possible threat to the design of the study is contamination, which may occur if participants in the control group are inadvertently exposed to the intervention.


Based on 2017-2020 data, obesity prevalence among 12-year-old to 19-year-old adolescents in the USA was 22.6% for boys and 21.7% for girls.1 The prevalence is higher among black than white 12-year-old to 19-year-old adolescents (29.8% and 23.1%, respectively2); and 10-year-old to 19-year-old adolescents from low-income households (≤138% federal poverty level) are more likely to have obesity (22.8%) than those of higher socioeconomic status (17.3%3). Without effective interventions, the Healthy People 2030 obesity target of 15.5% for adolescents may not be achieved.4

Contributing to the obesity problem and increasing the risk for chronic conditions, 76.1% of high school students do not attain the recommended ≥60 minutes/day of physical activity (PA), 75.0% do not eat breakfast daily, 45.3% eat vegetables <1 time/day, 47.1% eat fruit or drink 100% fruit juice <1 time/day and 14.7% drink sugar-sweetened soda/pop ≥1 time/day.5 Further augmenting the risk among adolescents, pubertal changes occur in the years immediately preceding high school that can contribute to insulin resistance.6 This information indicates that health-promoting interventions are needed before high school (ie, ages 10–13 years) so that young adolescents can begin to establish healthy behaviours to reduce their risk for adverse outcomes.7

Given that meeting PA and nutrition recommendations can be difficult for economically disadvantaged and/or minority status adolescents, reaching this population is essential to reduce obesity-related disparities.8 To accomplish this task, we designed a three-component (after-school club for adolescent engagement in PA and healthy eating/cooking activities, parent social networking website and parent meetings), 16-week intervention-based study called Guys/Girls Opt for Activities for Life (GOAL). Although targeting schools is recommended to reach under-represented adolescents in underserved communities,9 the lack of substantial efficacy of school-based interventions in reducing the prevalence of obesity may indicate a need to also target the home by actively involving parents to assist their adolescents.10 However, optimal approaches to increase parental support for improving under-represented adolescents’ moderate-to-vigorous physical activity (MVPA) and diet quality have not yet been clearly identified.11 Addressing this problem is imperative because adolescents who have not yet reached high school still rely on their parents for assistance.12 13

Based on findings from our comprehensive literature search, this study may be the first to include the three components proposed in GOAL in an intervention implemented with individuals from underserved urban areas, as this demographic is at higher risk for obesity.14

Aims and hypotheses

This trial’s primary purpose is to evaluate any effect of the GOAL intervention, compared with the control condition (usual school offerings), on improving: (1) adolescents’ % body fat (%BF; primary outcome), MVPA, diet quality and cardiorespiratory fitness (CRF) from 0 to 4 months; (2) body mass index (BMI), overweight/obesity (OW/O) percentage and quality of life (QOL) from 0 to 4 months and to 13 months; and (3) perceived social support, self-efficacy and motivation from 0 to 4 months with evaluation of any mediating effect on adolescent PA and diet quality. An exploratory aim is to evaluate any effect of the GOAL intervention, compared with control, on improving parents’/guardians’ (henceforth referred to as parents) home environment, MVPA and diet quality from 0 to 4 months; and BMI from 0 to 4 months and to 13 months.

Primary hypothesis

From 0 (baseline) to 4 months (immediate post-intervention) and to 13 months post-baseline (9-month post-intervention follow-up (F/U)), adolescents in the GOAL intervention, compared with control, will have greater reduction in %BF (≥2.3%15 16).

Secondary hypotheses

From 0 to 4 months, adolescents in GOAL intervention, compared with controls, will have higher MVPA, diet quality and CRF; and from 0 to 4 months and to 13 months, greater reduction in OW/O percentage and BMI and better QOL. Perceived social support, self-efficacy and motivation will mediate the effect of intervention on adolescents’ PA and diet quality.



GOAL is an individual randomised trial (2019–2026) involving 14 schools in the Midwestern USA. The study was on hold from 2020 to 2021 due to school closures associated with COVID-19 and from 2021 to 2022 due to COVID-related variants and school closures/restricted access to students. In the 2022–2023 academic years, the study was successfully conducted in four schools. Five schools will be included in 2023–2024 and also in 2024–2025.

Schools are selected based on the following criteria: (1) location in underserved urban community; (2) enrolment >150 adolescents in each school or more than double the number of adolescents needed (n=63/school) in any combination of fifth, sixth, seventh and/or eighth grade; and (3) racially and ethnically diverse student body (currently, targeted schools range between 31% and 100% minority race/ethnicity) including ≥49% enrolled in the free and reduced-price lunch programme. Schools are excluded if administrators are not interested in participating or cannot guarantee availability at 9-month post-intervention F/U.


We plan to enrol adolescents and one parent per adolescent (as support person; 882 dyads total) and then within each school randomly assign each dyad to receive the intervention or control condition. Figure 1 depicts the study flow chart.

Figure 1

Flow chart of study design for Guys/Girls Opt for Activities for Life trial.

Eligibility criteria

Adolescent inclusion criteria are: (1) enrolled in fifth through eighth grade (ages 10–14 years); (2) available and willing to participate in GOAL, including the after-school club conducted 2 days/week for 13 weeks; (3) available for F/U (9 months after intervention ends); (4) able to read, understand and speak English or have interpreter; and (5) able to identify one parent willing and able to serve as a support person and complete study activities. Exclusion criteria are: (1) mental or physical health condition precluding safe MVPA; and/or (2) taking medications that alter appetite, weight or growth; (3) unsatisfactory standing with the school (academic/behavioural17).

Parent inclusion criteria are: (1) have a student in fifth to eighth grade; (2) ≥18 years of age; (3) available and willing to participate; (4) able to read, understand and speak English or have an interpreter; (5) have internet access and device for accessing website and (6) mentally and physically able to serve as a support person. Exclusion criteria are: (1) mental or physical health condition precluding engagement in safe MVPA and healthy meal preparation with adolescent; (2) not interested in using a private social networking website and/or (3) not interested in learning to post on private social website.


Before the start of the school year, researchers attend open houses to inform parents and adolescents when an assembly will occur and to distribute flyers about the study. At the beginning of each school year, the project manager (PM) schedules recruitment assemblies so that study team members can meet with adolescents in their respective schools.

During each assembly, study team members share information about the study and invite adolescents to participate. Adolescents are told that they and one parent will be randomly assigned to either the intervention or usual school activities and that both parents and adolescents can receive compensation for their time to participate in data collection activities. Adolescents are informed that an adult chosen by the parent is allowed to serve as the support person if their parent is unable to participate.

Adolescents receive a flyer with a QR link to the assent form, parents to the consent form and both to an eligibility screening tool and baseline survey. Adolescents are asked to share information with their parents. School administrators also send an email (including flyer and QR code) to parents to share study information and invite them to participate with their adolescent. Parents and adolescents are asked to complete forms online within 48 hours if interested in participating. Parents are also invited to participate with their adolescents by researchers present at various school events, such as sporting, registration and conferences. If acceptable to school administrators, the school’s social media site (eg, Facebook page), email or text messages are used to inform parents and adolescents about the study and invite them to participate. A link is provided for parents and adolescents to complete forms online. Recruitment also occurs at lunch, during study/library periods and in classrooms or other venues. A 90 s video developed by the researchers is shown at each school. Study flyers are available in classrooms or other areas in the school for adolescents to take home. Strategies used may vary in each school depending on the permission and recommendations from school administrators. Response rates will be recorded. The PM and measurement coordinator (MC) identify adolescents and parents meeting eligibility criteria.

During the first year (fall 2022), we enrolled 218 adolescents and 211 parents from four schools. Although we did not reach our goal of 63 dyads per school, the recruitment strategies exceeded our demographic target of ≥40% black participants with an enrolment of 146 black adolescents (67.0%). Only forty-eight (22.0%) adolescents were identified as white. Over 60% of parents reported family incomes <US$50 000 per year with 34% having family incomes <US$30 000 per year. Approximately 52.8% of this sample of adolescents was overweight or obese.


The GOAL intervention is based on Self-Determination Theory (SDT18) and the Information-Motivation-Behavioural Skills (IMB) Model.19 GOAL targets the school and home environment to increase young adolescents’ PA and healthy eating by increasing motivation, self-efficacy and social support. Each intervention component incorporates SDT’s proposed three basic needs for promoting autonomous motivation to drive positive behaviour change: competence, autonomy and relatedness. Table 1 includes details regarding each of the following three intervention components:

Table 1

GOAL intervention (three components: after-school GOAL club; three meetings; social networking website)

After-school GOAL club

The club offers PA and healthy eating/cooking skill-building sessions to help adolescents improve their PA and nutritional habits (competence; self-efficacy) with social support from peers and coaches (relatedness). The GOAL club provides education and resources (competence) to help adolescents choose what to do outside the club. Adolescents can also provide some input regarding club activities (autonomy).

Three parent meetings

The parent meetings are conducted to provide information, encouragement and behavioural strategies to build adolescents’ skills (competence; self-efficacy) regarding PA and healthy eating/cooking with social support from parents and others to enhance relatedness and autonomy to increase adolescents’ motivation for both behaviours. Meeting reminders via text messages, phone calls, emails and the website are sent to parents.

GOAL social networking website

The website offers information, encouragement and behavioural strategies each week to help parents enhance their adolescent’s perceived social support, self-efficacy and motivation to increase adolescents’ PA and healthy eating. The website is accessible by parents via any smartphone or computer so that parents can complete weekly tasks. Parents having an adolescent in the same school are included in their own group so parents in each group can privately interact with each other.

Training for research team members

Prior to the start of the intervention, all research assistants (RAs) complete the university’s online (1) human subjects’ protection, (2) Health Insurance Portability and Accountability Act, (3) Good Clinical Practice and (4) research ethics training videos.

Training for intervention delivery

In early fall of each intervention year, the PM and intervention coordinator (IC) provide two 4-hour training sessions (8 hours total) for the GOAL club coaches to discuss the club protocol and proper communication techniques to use with adolescents. To prevent drift, the PM and IC conduct additional training sessions during the intervention if needed (based on process evaluation data).

The PM and/or IC provide(s) a 4-hour training for the moderator to discuss the protocol for monitoring website activities. The trained moderator will review all website communications to ensure adherence to policies.

Training for data collection

Prior to the start of the school year, the MC conducts two 4-hour sessions (8 hours total) to train RAs. Before collecting data, RAs must demonstrate proficiency regarding each procedure. The MC oversees all sessions to ensure fidelity to the data collection protocol. The MC conducts 4-hour booster training sessions for all data collectors immediately prior to both post-intervention data collection and 9-month post-intervention F/U. Data are entered electronically into Research Electronic Data Capture (REDCap) hosted on the university’s servers.

After baseline measures are obtained, researchers contact parents by email to inform them of their randomisation status. The measurement and intervention teams work independently so members of the former group (except for MC) are blinded to each participant’s randomisation status throughout the study. Adolescents, parents, principals and school staff are not told about hypotheses.

Training for process evaluation

Prior to the start of the school year, the PM and MC conduct one 4-hour session to train RAs in using observation tools and quantitative checklists to evaluate dose delivered and fidelity to the study protocol.


Table 2 includes the schedule of the following assessments:

Table 2

Schedule of assessments for GOAL trial

Per cent body fat (%BF) and BMI

Following the RJL Quantum Systems (RJL Systems, Clinton Township, Michigan, USA) protocol, bioelectric impedance analysis (BIA) is used to estimate %BF.20 21 Electrodes are placed: one on right hand, wrist, foot and ankle. In adolescents, intraclass correlation coefficients ≥0.99 demonstrate test–retest reliability; and hydrostatic weighing and BIA are correlated (r≥0.9722). High levels of agreement between total %BF using BIA and dual-energy X-ray absorptiometry have been reported.23

Height without shoes is assessed with a Shorr Board to the nearest 0.10 cm (Weigh and Measure, LLC, Olney, Maryland, USA), and weight in kg to nearest 0.10 kg is measured using a scale (Tanita, Tokyo, Japan). Two height and weight measurements are taken and averaged. The online SAS programme for CDC Growth Charts is used to estimate each adolescent’s BMI, BMI z-score and percentile for age and sex.24

Quality of life

The 23-item Pediatric QOL Inventory25 26 measures health-related QOL. Adolescents indicate how much of a problem something has been during past month (0=never to 4=almost always). Items are reverse-scored and transformed to a 0–100 scale (0=100, 1=75, 2=50, 3=25, 4=0). Higher scores=better QOL.

Moderate-to-vigorous physical activity

Minutes of MVPA/hour are assessed via ActiGraph GT3X+ and wGT3X-BT27 28 (ActiGraph, Pensacola, Florida, USA) accelerometers.29 Monitors are initialised and set to begin data collection the morning after they are distributed to adolescents at school. Devices are worn on the right hip on an elastic belt. Data from at least 7 days are collected (raw mode, 30 Hz) and downloaded to the same computer used to initialise monitors.30 To determine intensity, data will be processed using the GGIR package in R with Hildebrand hip-based, ENMO thresholds.31–33

Diet quality

Adolescents complete two 24-hour dietary recalls over 1–2 weeks at baseline and post-intervention. The University of Minnesota Nutrition Data System for Research (University of Minnesota Nutrition Coordinating Center, Minneapolis, Minnesota, USA) is used. The MC, who completed NDSR training, trains RAs to collect data from each adolescent via phone. The 24-hour recall method, including phone interviews, has been validated with children.34–36

Cardiorespiratory fitness

The Progressive Aerobic Cardiovascular Endurance Run (PACER37) 15-metre shuttle run is used to estimate aerobic capacity. Following audio cues, small groups of adolescents run from one line to another on a flat surface until they are unable to complete two laps within time allowed. RAs record the number of completed laps (higher number equates to greater CRF), which are converted to maximum oxygen consumption (VO2max, mL/kg/min) for analysis.38

Cognitive and affective mediating variables

Cognitive and affective mediating variables are assessed (Qualtrics, Provo, Utah, USA) with measures that have demonstrated reliability and validity with adolescents. Perceived self-efficacy for PA is measured with the 6-item Perceived PA Self-Efficacy Scale.39–41 Response choices range from ‘not sure at all’ to ‘very sure’. Motivation is determined from 12 items from the Behavioral Regulation in Exercise Questionnaire (BREQ-3) that assess identified and integrated regulation and intrinsic motivation.42 43 Four response choices range from ‘not true for me’ to ‘very true for me’. Social support for PA received from parents is measured via an 8-item Social Support Scale, and social support for PA from friends is assessed with three items modified from a scale assessing peer support. Five response choices for these two support scales range from ‘never’ to ‘very often’. Self-efficacy for healthy eating is measured using the 9-item Self-efficacy for Healthy Eating Scale. Response choices range from ‘not at all sure’ to ‘very sure’. Social Support for Healthy Eating from family and friends is rated using eight items from the Family and Friend Support for Healthy Eating Scale.44 Response choices range from ‘never’ to ‘very often’. Motivation for healthy eating is examined using 12 items from the Regulation of Eating Behaviors Scale.45 Five response choices range from not very true for me’ to ‘very true for me’.

Demographic variables

Items on the consent/assent form include: age, birthdate, sex/gender, academic grade, ethnicity, race and SES (three items: adolescent participation in free or reduced-price lunch programme, parent education and annual family income). Using the 5-item Pubertal Development Scale,46 boys and girls rate themselves on growth spurt, body hair (underarm) and skin changes. Boys answer questions on voice change and facial hair; girls answer questions on breast growth and menarche. Response choices are: (1) no; (2) barely; (3) definitely; or (4) development complete, except for menarche (1=no; 4=yes, menstruation started). A higher summed score=more advanced stage (pre-pubertal; early, middle, late puberty; post-pubertal47).

Parent measures

Parents complete the International PA Questionnaire (IPAQ) to measure MVPA,48 the Block Fruit-Vegetable-Fibre Screener for diet quality49 and the Family Nutrition and Physical Activity Screener to assess the home environment50 and provide self-reported height and weight measurements for BMI calculations.

Process evaluation

After-school GOAL club

Club coaches use the internet-based programme to record reach (eg, adolescents’ attendance at GOAL club). To assist researchers in evaluating dose delivered, the GOAL club manager records the types of activities offered during the club. Using an observation tool and a quantitative checklist with a rating scale, a trained process evaluator evaluates an entire club session in the first month, at the midpoint and near the end of the intervention period. The checklist includes items for assessing dose delivered or staff adherence to the club protocol and evaluating fidelity or the degree that the club reflects the IMB Model and SDT. The IC intervenes as needed with the club manager and coaches to increase interventionist adherence to the club protocol. To evaluate dose received, each adolescent completes two multiple-choice items (one to evaluate attention to information provided; one to determine knowledge of skills engaged in) at the end of both the PA session and the healthy eating plus cooking session (four items total/club day).

Overall evaluation of intervention components—immediately post-intervention

During post-intervention data collection, adolescents in the intervention group respond to the Adolescent GOAL Intervention Evaluation Instrument created by the researchers to report satisfaction with the club and parent–adolescent meeting. Parents respond to the Parent GOAL Intervention Evaluation Instrument created by the researchers to report satisfaction with the three meetings and social networking website.

Parent–adolescent meetings and social networking for parents

Process evaluators not involved in other study areas record meeting attendance (reach) and complete a checklist to indicate if objectives were met (dose delivered). Parents complete a brief multiple-choice quiz so the researchers can evaluate the degree that presented information was acquired (dose received). The website records parent participation (reach), all researcher postings (dose delivered), and each parent’s task completion and the responses to two multiple-choice questions each week asking about flyer information (dose received). Process evaluators evaluate if meetings and flyers reflect the SDT and IMB Model (fidelity).

Sample size determination and data analysis

Power calculations were conducted using PASS V.15 (NCSS, LLC, Kaysville, Utah, USA). In calculating sample size, we assume two-sided type I error alpha=0.05. A study in New York City schools showed ICC=0.037 for %BF.51 Power analysis is based on intention-to-treat (ITT) principle where all participants including dropouts are analysed based on their randomised group regardless of treatment received.52 53 The power analyses show that N=882 will yield 90% power to detect an effect size of Cohen’s d=0.28 SD, corresponding to a 2.3% reduction in %BF assuming a 20% dropout rate and an ICC=0.03 for adolescents nested in the same club. There is no nesting among control group adolescents; hence, the study’s senior biostatistician will guide the data manager (blinded) in allocating fewer adolescents in the control groups.

Data analysis

Primary analysis

Analysis will be based on the ITT principle.52 53 To account for dependence of observations nested within club and within school as well as dependence within person measured repeatedly over time, analyses will be conducted using a multilevel model approach54 incorporating baseline covariates as needed.55 56 Multilevel generalised linear models57 58 will be fit for discrete outcomes using appropriate link functions. Assumptions of normality for continuous outcome variables will be evaluated by checking residuals; normalising transformations or generalised linear mixed effect models will be used if warranted.57 Random effects for club indexed by sex and for school will be included to account for interdependence within club for boys and girls separately nested within school. The within-subject correlation will be modelled using an autocorrelation covariance structure on the residuals. Relevant contrast will be estimated to compare changes from baseline to post-intervention and 9-month post-intervention F/U between intervention and control groups and derive inferences on the intervention effect at each time point. The study biostatistician and data manager will assess if the intervention effect is uniform by sex, race and weight status by including interaction terms of each of the subgroup variables (eg, sex) with group and time variables. Also, they will run subgroup analysis stratified by sex, race and weight status to assess the magnitude of the intervention effect among different subgroups. The statistical significance is set at p value <0.05. There is no interim analysis or early stopping rule.

Secondary analysis

For the secondary outcomes, multilevel linear regression models will be used in a similar way to model intervention effect over time on MVPA, diet quality, CRF, OW/O percentage, BMI and QOL. Similar to the primary analysis, the biostatistician and data manager will test for moderation of each of sex, race and baseline weight status in the effect of intervention on secondary outcomes. Analysis based on the ITT principle will be of primary interest; however, a dose–response analysis will be performed to evaluate actual participation in the intervention and if it has an increased effect on outcomes.

Possible effect mediators or modifiers

Whether any intervention effects on each outcome are fully or partially mediated by social support, self-efficacy and motivation will be determined.59–65 Effect sizes will be calculated using estimates of standardised regression coefficients and 95% CIs. Per cent of variation mediated will be determined.66

Exploratory aim

We will explore the effect of GOAL versus control on parents’ perceived family nutrition and PA, MVPA and diet quality; and BMI at post-intervention and 9-month post-intervention F/U using multilevel models as described above. However, it is possible that the clustering effect due to club and school is negligible for parents’ outcomes and will be tested using Bayesian Information Criteria.

Incomplete data

Statistical models will incorporate missing at random mechanism67 and derived inferences using full information maximum likelihood methods. Baseline characteristics of those who dropped out will be compared by group to determine any attrition bias; if present, such variable will be used to control for. If the missing data are non-ignorable, sensitivity analysis will be performed.68–71 While maximum effort will be made to avoid missing data, we expect some data will still be missing. For ITT analysis, the biostatistician and data manager will impute missing values using statistical techniques, such as multiple imputations using PROC MI in SAS and IVEware SAS macro.72 73 Summary analysis will then be performed using SAS PROC MIANALYZE, where each dataset is analysed separately and a final estimate across all imputed data is derived.74

Ethics and dissemination

The research will be reported in accordance with Consolidated Standards of Reporting Trials recommendations.75 76 The Michigan State University Biomedical Institutional Review Board provided ethical approval, and school administrators gave approval to conduct the study. An independent Data Monitoring Committee comprised of a research associate dean (project safety officer) and four senior-level researchers (including paediatrician and statistician) review materials on the study progress and any data or adverse events (biannually or as needed). The study is registered in Findings will be shared via the trial registration database, peer-reviewed publications in scientific journals (concurrent uploading to PubMed Central for public use), professional conferences, organisation newsletters and media releases.


The GOAL intervention is primarily designed to reduce the OW/O prevalence noted among under-represented adolescents. Findings from our pilot study that tested the GOAL intervention indicated the three components were feasible in a school setting and acceptable to parents and adolescents.77 Conducting this individual randomised trial with a large sample is critical for evaluating the efficacy of the intervention. The multi-year trial will help in refining and strengthening the intervention, identifying key theoretical mediators influencing adolescents’ PA and nutrition, shedding new light on relationships among the included variables and testing a novel approach for involving parents. Information acquired can be used to design future interventions directed toward promoting health equity among at-risk under-represented adolescents and their parents in underserved communities.

Ethics statements

Patient consent for publication

Ethics approval

The study has been approved by the Michigan State University Biomedical Institutional Review Board (#00002538)


The authors would like to thank the school administrators, teachers, and staff for assisting the research team to conduct the study in their respective schools. The authors would also like to thank the parents/guardians and adolescents for their participation. The authors are also grateful for the assistance received from Satya Subedi, a student in the Michigan State University MSN Family Nurse Practitioner program, who assisted with checking and carefully formatting the references.



  • Contributors LBR and JL conceived and designed the study with support from KAP, NK, JMK and KR. LBR wrote the initial draft of the manuscript. KAP and JMK provided written content related to physical activity and nutrition. LBR, JL, KAP, NK, JMK and KR participated in the development of the protocol and data acquisition methods. NK developed the statistical analysis plan. NK and HM provided statistical support and managed the data. LBR, AH, LH and SD provided oversight of the study, including overall study management, data collection and intervention implementation. All authors read and provided a critical review and editing of the manuscript and approved the final version.

  • Funding Research reported in this publication was supported by the National Heart, Lung, And Blood Institute of the National Institutes of Health under Award Number R33HL144896.

  • Disclaimer The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

  • Competing interests None declared.

  • Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.

  • Provenance and peer review Not commissioned; peer reviewed for ethical and funding approval prior to submission.