Understanding risk and causal mechanisms for developing obesity in infants and young children: A National Institutes of Health workshop.

Obesity in children remains a major public health problem, with the current prevalence in youth ages 2-19 years estimated to be 19.7%. Despite progress in identifying risk factors, current models do not accurately predict development of obesity in early childhood. There is also substantial individual variability in response to a given intervention that is not well understood. On April 29-30, 2021, the National Institutes of Health convened a virtual workshop on "Understanding Risk and Causal Mechanisms for Developing Obesity in Infants and Young Children." The workshop brought together scientists from diverse disciplines to discuss (1) what is known regarding epidemiology and underlying biological and behavioral mechanisms for rapid weight gain and development of obesity and (2) what new approaches can improve risk prediction and gain novel insights into causes of obesity in early life. Participants identified gaps and opportunities for future research to advance understanding of risk and underlying mechanisms for development of obesity in early life. It was emphasized that future studies will require multi-disciplinary efforts across basic, behavioral, and clinical sciences. An exposome framework is needed to elucidate how behavioral, biological, and environmental risk factors interact. Use of novel statistical methods may provide greater insights into causal mechanisms.

Prevención transfronteriza de la obesidad infantil: comentario de los National Institutes of Health.

En respuesta al aumento de las tasas de obesidad infantil, Estados Unidos y algunos países de Latinoamérica han financiado numerosos estudios que analizan estrategias e intervenciones innovadoras. A pesar de ello, los avances han sido lentos, irregulares y esporádicos, lo cual demuestra la necesidad de intensificar el intercambio de conocimientos y la colaboración en la investigación para acelerar la adaptación e implementación de intervenciones prometedoras en el campo de la obesidad infantil. Con la intención de compartir resultados de estudios, problemas y estrategias de intervención de probada eficacia entre los investigadores latinoamericanos y estadounidenses (especialmente los que trabajan con poblaciones latinas y latinoamericanas), los National Institutes of Health (NIH) reunieron a investigadores de Estados Unidos y Latinoamérica para destacar las sinergias entre los estudios de Latinoamérica y los realizados en poblaciones latinas de Estados Unidos. El fin último de esta iniciativa fue catalizar nuevas relaciones e identificar preguntas y estrategias comunes para la investigación. Este artículo se centra en la investigación y las prioridades de los NIH en materia de prevención de la obesidad infantil, así como en las áreas para futuras acciones, incluidos los planes generales de los NIH y las inversiones de sus institutos, centros y oficinas en áreas concretas relacionadas con la prevención de la obesidad infantil en Latinoamérica y en las poblaciones latinas de Estados Unidos.

Childhood obesity prevention across borders: A National Institutes of Health commentary.

In response to the increasing rates of childhood obesity, the United States and countries across Latin America have invested in research that tests innovative strategies and interventions. Despite this, progress has been slow, uneven, and sporadic, calling for increased knowledge exchange and research collaboration that accelerate the adaptation and implementation of promising childhood obesity interventions. To share research results, challenges, and proven intervention strategies among Latin American and US researchers, particularly those working with Latino and Latin American populations, the National Institutes of Health (NIH) convened researchers from the United States and Latin America to highlight synergies between research conducted in Latin America and among Latino populations in the United States with the goal of catalyzing new relationships and identifying common research questions and strategies. This article highlights the NIH's research and priorities in childhood obesity prevention as well as areas for future direction, including overarching NIH plans and NIH institutes, centers, and offices investments in specific areas related to childhood obesity prevention in Latin America and/or among Latino populations in the United States.

Physiology of the Weight-Reduced State: A Report from a National Institute of Diabetes and Digestive and Kidney Diseases Workshop.

Preventing regain of lost weight is the most difficult challenge in the treatment of obesity. The National Institute of Diabetes and Digestive and Kidney Diseases convened a workshop, "The Physiology of the Weight-Reduced State," on June 3 to 4, 2019, in order to explore the physiologic mechanisms of appetitive and metabolic adaptation that take place in the weight-reduced state and counter an individual's efforts to maintain reduced weight following weight loss.

Feasibility of a Smartphone App with Mindfulness Training for Adolescent Smoking Cessation: Craving to Quit (C2Q)-Teen.

OBJECTIVES: The use of mobile technology for smoking cessation holds promise for adolescents, who do not typically access traditional treatments, but most are not grounded in theory or mechanism. Operant conditioning theory suggests an addictive smoking loop is formed between nicotine use and affective states, leading to habitual cue-induced craving and automatic behavior; mindfulness training may bring automated smoking behavior into awareness, so smokers may work mindfully with cravings. Mindfulness training delivered via smartphone technology therefore has potential to help adolescent smokers break this addictive loop and quit smoking. This pair-matched cluster-randomized controlled school-based pilot study evaluated program feasibility and preliminary smoking outcomes in relation to intervention engagement. METHODS: Six high schools were pair matched and randomly assigned to one of three interventions: (1) mindfulness training delivered via mobile smoking cessation application (Craving to Quit, C2Q), (2) NCI's QuitSTART smoking cessation application (NCI), and (3) written cessation materials (Materials). Adolescents (n = 146) smoking 5 or more cigarettes per day were recruited. Interventions were implemented over four weeks and study assessments were collected at baseline and 3- and 6- month follow-up, including self-reported 7-day point prevalence abstinence, program usage, smoking-related measures, and psychosocial factors. RESULTS: Overall cotinine-validated abstinence at 6 months was 15.8% and was similar between conditions. Odds of abstinence increased with each quartile increase in app/materials use with no significant differences between conditions (OR=1.60 (C2Q), 1.66 (Materials), and 2.69 (NCI)). Of participants still smoking at 6 months, for each quartile increase in engagement the number of cigarettes smoked in the previous 7 days showed a significantly greater decline in the C2Q condition (-5.71) compared to the Materials (-0.95) and NCI (+7.73) condition (p=0.02 for differences between conditions). CONCLUSIONS: Cotinine-validated abstinence was similar between intervention conditions and tended to increase with greater engagement in each condition. Greater C2Q app engagement among continuing smokers was associated with a significantly greater decline in number of cigarettes smoked compared to the other conditions. The Craving to Quit (C2Q) mobile smoking cessation application with mindfulness training was feasible to use and has promise in assisting adolescents to quit or decrease cigarette smoking. CLINICAL TRIAL REGISTRATION: Developing a Smartphone App with Mindfulness Training for Teen Smoking Cessation: ClinicalTrials.gov Identifier: NCT02218281.

Psychosocial, behavioral and clinical correlates of children with overweight and obesity.

BACKGROUND: Psychological and behavioral correlates are considered important in the development and persistence of obesity in both adults and youth. This study aimed to identify such features in youth with severe obesity (BMI ≥ 120% of 95thpercentile of sex-specific BMI-for-age) compared to those with overweight or non-severe obesity. METHODS: Youth with BMI ≥ 85th percentile were invited to participate in a prospective research registry where data was collected on attributes such as family characteristics, eating behaviors, dietary intake, physical activity, perception of health and mental well-being, and cardiometabolic parameters. RESULTS: In a racially/ethnically diverse cohort of 105 youth (65% female, median age 16.1 years, range 4.62-25.5), 51% had severe obesity. The body fat percent increased with the higher levels of obesity. There were no differences in the self-reported frequency of intake of sugar sweetened beverages or fresh produce across the weight categories. However, the participants with severe obesity reported higher levels of emotional eating and eating when bored (p = 0.022), levels of stress (p = 0.013), engaged in fewer sports or organized activities (p = 0.044), and had suboptimal perception of health (p = 0.053). Asthma, depression and obstructive sleep apnea were more frequently reported in youth with severe obesity. The presence of abnormal HDL-C, HOMA-IR, hs-CRP and multiple cardiometabolic risk factors were more common among youth with severe obesity. CONCLUSIONS: Youth with severe obesity have identifiable differences in psychosocial and behavioral attributes that can be used to develop targeted intervention strategies to improve their health.

Perspective: Dietary Biomarkers of Intake and Exposure-Exploration with Omics Approaches.

While conventional nutrition research has yielded biomarkers such as doubly labeled water for energy metabolism and 24-h urinary nitrogen for protein intake, a critical need exists for additional, equally robust biomarkers that allow for objective assessment of specific food intake and dietary exposure. Recent advances in high-throughput MS combined with improved metabolomics techniques and bioinformatic tools provide new opportunities for dietary biomarker development. In September 2018, the NIH organized a 2-d workshop to engage nutrition and omics researchers and explore the potential of multiomics approaches in nutritional biomarker research. The current Perspective summarizes key gaps and challenges identified, as well as the recommendations from the workshop that could serve as a guide for scientists interested in dietary biomarkers research. Topics addressed included study designs for biomarker development, analytical and bioinformatic considerations, and integration of dietary biomarkers with other omics techniques. Several clear needs were identified, including larger controlled feeding studies, testing a variety of foods and dietary patterns across diverse populations, improved reporting standards to support study replication, more chemical standards covering a broader range of food constituents and human metabolites, standardized approaches for biomarker validation, comprehensive and accessible food composition databases, a common ontology for dietary biomarker literature, and methodologic work on statistical procedures for intake biomarker discovery. Multidisciplinary research teams with appropriate expertise are critical to moving forward the field of dietary biomarkers and producing robust, reproducible biomarkers that can be used in public health and clinical research.

Childhood obesity research at the NIH: Efforts, gaps, and opportunities.

Childhood obesity is a major public health challenge. This article describes an overview of the National Institutes of Health (NIH) behavioral and social sciences childhood obesity research efforts. The overview will highlight five areas of childhood obesity research supported by the NIH: (a) basic behavioral and social sciences; (b) early childhood; (c) policies, programs, and environmental strategies; (d) health disparities; and (e) transagency and public-private collaboration. The article also describes potential gaps and opportunities in the areas of childhood obesity and severe obesity, measurement, and sleep.

Working toward precision medicine approaches to treat severe obesity in adolescents: report of an NIH workshop.

Adolescent severe obesity is a prevalent, chronic, and serious disease with few effective and safe treatment options. To address this issue, a National Institutes of Health-sponsored workshop entitled "Developing Precision Medicine Approaches to the Treatment of Severe Obesity in Adolescents," was convened, bringing together a multidisciplinary group of experts to review the current state of the science and identify (1) what is known regarding the epidemiology and biopsychosocial determinants of severe obesity in adolescents, (2) what is known regarding effectiveness of treatments for severe obesity in adolescents and predictors of response, and (3) gaps and opportunities for future research to develop more effective and targeted treatments for adolescents with severe obesity. Major topical areas discussed at the workshop included: appropriate BMI metrics, valid measures of phenotypes and predictors, mechanisms associated with the development of severe obesity, novel treatments informed by biologically and psychosocially plausible mechanisms, biopsychosocial phenotypes predicting treatment response, standardization of outcome measures and results reporting in research, and improving clinical care. Substantial gaps in knowledge were identified regarding the basic behavioral, psychosocial, and biological mechanisms driving the development of severe obesity and the influence of these factors on treatment response. Additional exploratory and observational studies are needed to better understand the heterogeneous etiology of severe obesity and explain the high degree of variability observed with interventions. Tailored treatment strategies that may be developed by achieving a better understanding of individual differences in genetic endowment, clinical, metabolic, psychological, and behavioral phenotypes, and response to environmental exposures need to be tested. It is anticipated that these recommendations for future research, including strategies to enhance methodological rigor, will advance precision medicine approaches to treat severe obesity in adolescents more effectively.

BMI Trajectories from Birth to Young Adulthood.

OBJECTIVE: This study aimed to compare BMI trajectories from childhood to early adulthood in those with overweight and/or obesity versus severe obesity. METHODS: Longitudinal BMI values (2,542 measurements) were calculated from measured heights and weights for 103 children, adolescents, or young adults with overweight, obesity, or severe obesity. Segmented regression with splines was used to model BMI trajectories. RESULTS: Sixty-nine participants were classified as ever having severe obesity versus 34 who never had severe obesity. Trajectories and slopes did not differ by sex or race/ethnicity. Compared with those who never had severe obesity, BMI was higher in the group with severe obesity at all ages, and BMI slope was higher for those with severe obesity at age 14 (P = 0.002), with peak slope occurring later (18 years vs. 16 years) and higher (4.5 ± 0.5 kg/m2 /y vs. 2.9 ± 0.5 kg/m2 /y; P < 0.02). In the group without severe obesity, BMI fell below zero by the mid-20s (-0.3 ± 0.6 kg/m2 /y); in those with severe obesity, BMI slope never reached zero (0.9 ± 0.5 kg/m2 /y). CONCLUSIONS: Youth with severe obesity, compared with their peers without, started with higher BMIs, had more rapid rates of BMI increase beginning at age 14, as well as a higher peak and longer period of increase, and never achieved weight stabilization.

Maternal IgG immune complexes induce food allergen-specific tolerance in offspring.

The role of maternal immune responses in tolerance induction is poorly understood. To study whether maternal allergen sensitization affects offspring susceptibility to food allergy, we epicutaneously sensitized female mice with ovalbumin (OVA) followed by epicutaneous sensitization and oral challenge of their offspring with OVA. Maternal OVA sensitization prevented food anaphylaxis, OVA-specific IgE production, and intestinal mast cell expansion in offspring. This protection was mediated by neonatal crystallizable fragment receptor (FcRn)-dependent transfer of maternal IgG and OVA immune complexes (IgG-IC) via breast milk and induction of allergen-specific regulatory T (T reg) cells in offspring. Breastfeeding by OVA-sensitized mothers or maternal supplementation with IgG-IC was sufficient to induce neonatal tolerance. FcRn-dependent antigen presentation by CD11c+ dendritic cells (DCs) in offspring was required for oral tolerance. Human breast milk containing OVA-IgG-IC induced tolerance in humanized FcRn mice. Collectively, we demonstrate that interactions of maternal IgG-IC and offspring FcRn are critical for induction of T reg cell responses and control of food-specific tolerance in neonates.

Impact of an Electronic Template on Documentation of Obesity in a Primary Care Clinic.

Identification of obesity at well-child care (WCC) examinations is a step toward intervention. Studies have shown suboptimal documentation in primary care clinics that can improve with the use of electronic health records (EHRs). This study investigated the impact of a standardized EHR template on documentation of obesity at WCC visits and its impact on physician behavior. A cohort of 585 children with severe early onset obesity (body mass index >99th percentile, age <6 years) was identified with an electronic algorithm. Complete records of visit notes were reviewed to extract history taking, counseling, and recording of obesity at a WCC visit. Use of a standardized EHR template for WCC visits is associated with improvement in rates of documentation of obesity (47% vs 34%, P < .01), without interruption of workflow. Documentation of obesity in the chart improved nutritional (66% vs 44%, P < .001) and physical activity counseling (23% vs 9%, P < .001).

Effect on Physical Activity of a Randomized Afterschool Intervention for Inner City Children in 3rd to 5th Grade.

BACKGROUND: Less than 45% of U.S. children meet the 60 min·d(-1) physical activity (PA) guideline. Structured after-school PA programing is one approach to help increase activity levels. This study aimed to evaluate the feasibility and short-term impact of a supervised after-school PA and nutrition education program on activity levels. METHODS: Forty-two 3rd-5th graders from an inner-city school in Boston, MA were randomly assigned to a 10-wk after-school program of either: 1) weekly nutrition education, or 2) weekly nutrition education plus supervised PA 3 d·wk(-1) at a community-based center. At baseline and follow-up, PA was measured using accelerometry and fitness (VO2max) was estimated using the PACER 15-m shuttle run. Additional measures obtained were non-fasting finger stick total cholesterol (TC) and glucose levels, waist circumference (WC), body mass index (BMI), percent body fat (%BF), and blood pressure (BP). Values are presented as mean±SE, unless noted otherwise. RESULTS: Thirty-six participants completed the study (mean±SD; age 9.7±0.9 years). Participants attended >80% of the sessions. After adjusting for accelerometer wear time and other design factors, light and moderate-to-vigorous PA (MVPA) increased in the nutrition+PA group (+21.5±14.5 and +8.6±8.0 min·d(-1), respectively) and decreased in the nutrition only group (-35.2±16.3 and -16.0±9.0 min·d(-1), respectively); mean difference between groups of 56.8±21.7 min·d(-1) (light PA, p = 0.01) and 24.5±12.0 min·d(-1) (MVPA, p = 0.04). Time spent in sedentary behaviors declined in the nutrition+PA group (-14.8±20.7 min·d(-1)) and increased in the nutrition only group (+55.4±23.2 min·d(-1)); mean difference between groups of -70.2±30.9 min·d(-1) (p = 0.02). Neither group showed changes in TC, BP, WC, %BF, BMI percentile, or fitness (p>0.05). CONCLUSIONS: The supervised afterschool community-based nutrition and PA program was well accepted and had high attendance. The changes in light PA and MVPA has potential to promote weight maintenance in inner-city elementary school children, however longer term studies with larger samples are needed. TRIAL REGISTRATION: ClinicalTrials.gov NCT01104038.

Factors Associated with Clinical Research Recruitment in a Pediatric Academic Medical Center--A Web-Based Survey.

BACKGROUND: One of the most difficult aspects of conducting clinical research is the ability to successfully recruit participants. Pediatric clinical research presents unique recruitment challenges that relate to the need for parental consent on behalf of a minor, child assent, and school attendance. Yet, this has been less well studied. We conducted a survey of investigators performing human subjects research in a single large academic pediatric hospital to better understand characteristics of studies with successful recruitment. METHODS: We conducted a web-based survey from September 2011 to December 2011 of all principal investigators with an Institutional Review Board approved human subjects protocol at Boston Children's Hospital, a pediatric Academic Medical Center. The survey captured various characteristics of the protocols including study design, staffing, resources, and investigator experience and training as well as respondents' perceived barriers and facilitators to recruitment. We used chi square tests and Mantel-Haenszel test for linear trend to examine the relationship between selected predictor variables and the binary outcome of successful vs. unsuccessful recruitment and multivariable logistic regression analyses to examine the simultaneous influence of potential predictors on each outcome. RESULTS: Among the 349 eligible investigators, 52% responded to the survey, and 181 with valid data were included in the analyses. Two-thirds of the 87 protocols closed to enrollment reached 80% or more of their target enrollment, whereas, only one-third of the 94 protocols actively recruiting were meeting 80% of their target. Recruitment method appeared to be the only significant and independent factor associated with achieving 80% or more of target enrollment in closed to enrollment protocols. Closed to enrollment protocols that used recruitment in person were 4.55 times (95% CI 1.30 to 15.93; p = 0.02) more likely to achieve 80% or more of their target enrollment when compared to those that used other recruitment methods. Other potentially modifiable factors such as number of study visits, study duration and investigator experience were suggestive of being meaningfully related to recruitment. CONCLUSION: Recruiting in person may promote reaching an acceptable target enrollment in pediatric as well as adult clinical research. Future research is needed on larger and more diverse samples to gain a better understanding of how the characteristics and qualifications of the individuals who conduct recruitment influence participant enrollment as well as how best to approach patient and families for their participation.

Providing food to treat adolescents at risk for cardiovascular disease.

OBJECTIVE: Diet modification is recommended to treat childhood cardiovascular (CV) risk factors; however, the optimal dietary strategy is unknown. METHODS: In a randomized trial, the effect of a low-fat (LF) and a low-glycemic-load (LGL) reduced-calorie diet were examined in youth with overweight/obesity with CV risk factors. Using a novel intervention, we delivered LF or LGL meals and nutrition education to the home for 8 weeks (Intensive Phase), followed by 4 months Maintenance without food provision. Between-group differences in the change in insulin area under the curve (InsAUC) by oral glucose tolerance test and other risk factors were analyzed. RESULTS: Overall, participants (n = 27) showed substantial improvement during the Intensive Phase, including InsAUC (-59 ± 18.2 µU/ml × 120 min, P = 0.004), total cholesterol (-9.9 ± 3.6 mg/dl, P = 0.01), weight (-2.7 ± 0.5 kg, P < 0.001), waist circumference (-3.1 ± 0.8 cm, P < 0.001), HOMA-IR (-1.7 ± 0.4, P < 0.001), systolic blood pressure (-5 ± 1.4 mm Hg, P = 0.002), and CRP (-0.1 ± 0.1 mg/dl, P = 0.04). There were minimal between-group differences; the LF group showed greater declines in HDL (P = 0.005) and fasting glucose (P = 0.01) compared to the LGL group. Improvements waned during Maintenance. CONCLUSIONS: Home delivery of LF or LGL diets resulted in rapid and clinically important improvements in CV risk factors that diminished without food delivery and did not differ based on dietary intervention. If scalable, food provision may represent an alternative nutrition treatment strategy.

Three-Year Improvements in Weight Status and Weight-Related Behaviors in Middle School Students: The Healthy Choices Study.

INTRODUCTION: Few dissemination evaluations exist to document the effectiveness of evidence-based childhood obesity interventions outside the research setting. OBJECTIVE: Evaluate Healthy Choices (HC), a multi-component obesity prevention program, by examining school-level changes in weight-related behaviors and weight status and the association of implementation components with odds of overweight/obesity. METHODS: We compared baseline and Year 3 school-level behavioral and weight status outcomes with paired t-tests adjusted for schools' socio-demographic characteristics. We used generalized estimating equations to examine the odds of overweight/obesity associated with program components. SETTING/PARTICIPANTS: Consecutive sample of 45 of 51 middle schools participating in the HC program with complete baseline and follow-up survey data including a subsample of 35 schools with measured anthropomentry for 5,665 7th grade students. INTERVENTION: Schools developed a multi-disciplinary team and implemented an obesity prevention curriculum, before and after school activities, environmental and policy changes and health promotions targeting a 5-2-1 theme: eat ≥ 5 servings/day of fruits and vegetables (FV), watch ≤ 2 hours of television (TV) and participate in ≥ 1 hours/day of physical activity (PA) on most days. MAIN OUTCOME MEASURES: 1) School-level percent of students achieving targeted behaviors and percent overweight/obese; and 2) individual odds of overweight/obesity. RESULTS: The percent achieving behavioral goals over three years increased significantly for FV: 16.4 to 19.4 (p = 0.001), TV: 53.4 to 58.2 (p = 0.003) and PA: 37.1 to 39.9 (p = 0.02), adjusting for school size, baseline mean age and percent female, non-Hispanic White, and eligible for free and reduced price lunch. In 35 schools with anthropometry, the percent of overweight/obese 7th grade students decreased from 42.1 to 38.4 (p = 0.016). Having a team that met the HC definition was associated with lower odds of overweight/obesity (OR = 0.83, CI: 0.71-0.98). CONCLUSIONS AND RELEVANCE: The HC multi-component intervention demonstrated three-year improvements in weight-related behaviors and weight status across diverse middle schools. Team building appears important to the program's effectiveness.

Using high-dose omega-3 fatty acid supplements to lower triglyceride levels in 10- to 19-year-olds.

BACKGROUND: Omega-3 fatty acids supplements lower triglyceride (TG) levels in adults; little pediatric information is available. We evaluated their effect in hypertriglyceridemic adolescents. METHODS: Twenty-five patients aged 10 to 19 years with TG levels 150 to 1000 mg/dL were randomized to 6 months double-blind trial of Lovaza (~3360 mg docosahexaenoic acid + eicosapentaenoic acid per day) versus placebo. RESULTS: Baseline mean TG levels were 227 mg/dL (standard deviation = 49). TG levels declined at 3 months in the Lovaza group by 54 ± 27 mg/dL (mean ± standard error; P = .02) and by 34 ± 26 mg/dL (P = .16) in the placebo group. The difference in TG lowering between groups was not significant (P = .52). There were no between-group differences in endothelial function, blood pressure, body mass index, C-reactive protein, or side effects. CONCLUSIONS: High-dose omega-3 fatty acid supplements are well tolerated in adolescents. However, declines in TG levels did not differ significantly from Placebo in this small study.

The contribution of school environmental factors to individual and school variation in disordered weight control behaviors in a statewide sample of middle schools.

We investigated the contribution of school environmental factors to individual and school variation in disordered weight control behaviors (DWCB). Analyses were based on self-report data gathered from 18,567 middle-school students in 2005 and publicly available data on school characteristics. We observed large differences across schools in percent of students engaging in DWCB in the past month, ranging from less than 1% of the student body to 12%. School-neighborhood poverty was associated with higher odds of DWCB in boys. Preventive strategies need to account for wide variability across schools and environmental factors that may contribute to DWCB in early adolescence.

Effect of the planet health intervention on eating disorder symptoms in Massachusetts middle schools, 2005-2008.

INTRODUCTION: The Planet Health obesity prevention curriculum has prevented purging and abuse of diet pills (disordered weight control behavior [DWCB]) in middle-school girls in randomized trials, but the effects of Planet Health on DWCB when implemented by schools under dissemination conditions are not known. METHODS: Massachusetts Department of Public Health and Blue Cross Blue Shield of Massachusetts disseminated Planet Health as part of the 3-year, Healthy Choices obesity prevention program in middle schools. We conducted an evaluation in 45 schools from fall 2005 to spring 2008. We gathered data from school staff to quantify intervention activities, and we gathered anonymous cross-sectional survey data from students on DWCB at baseline and Year 3 follow-up (n = 16,369). Multivariate logistic analyses with generalized estimating equations examined the effect of intervention activities on odds of students reporting DWCB at follow-up. RESULTS: Students in schools reaching a high number of youth with Planet Health lessons on reducing television viewing had lower odds of DWCB at follow-up (odds ratio [OR], 0.80 per 100 lesson-exposures; 95% confidence interval [CI], 0.74-0.85). In addition, reduced odds of DWCB at follow-up were found in schools with active staff teamwork (OR, 0.76; 95% CI, 0.66-0.86) and the presence of programs addressing television viewing goals with staff (OR, 0.38; 95% CI, 0.28-0.53). CONCLUSION: Combined evidence from efficacy and effectiveness trials and now from dissemination research indicates that appropriately designed obesity prevention programs can achieve DWCB prevention on a large scale.