Addressing childhood obesity in low-income, ethnically diverse families: outcomes and peer effects of MEND 7–13 when delivered at scale in US communities

Implementation of a large-scale, child weight management program in low-income, ethnically diverse communities provided an important opportunity to evaluate its effectiveness under service level conditions (i.e. provision as a primary care child weight management service). MEND 7–13 is a community-based, multi-component, childhood obesity intervention designed to improve dietary, physical activity and sedentary behaviors. It comprises twice weekly sessions for 10 consecutive weeks (35 contact hours) and is delivered to groups of children and accompanying parents/caregivers. The evaluation used an uncontrolled, repeated measures design. Overall, 3782 children with overweight or obesity attended 415 MEND 7–13 programs in eight US states, of whom 2482 children (65.6%) had complete data for change in zBMI. The intervention targeted low-income, ethnically diverse families. Changes in anthropometric, cardiovascular fitness and psychological outcomes were evaluated. A longitudinal multivariate imputation model was used to impute missing data. Peer effects analysis was conducted using the instrumental variables approach and group fixed effects. Mean changes in BMI and zBMI at 10 weeks were −0.49 kg/m2 (95% CI: −0.67, −0.31) and −0.06 (95% CI: −0.08, −0.05), respectively. Benefits were observed for cardiovascular fitness and psychological outcomes. Mean peer reduction in zBMI was associated with a reduction in participant zBMI in the instrumental variables model (B = 0.78, P = 0.04, 95% CI: 0.03, 1.53). Mean program attendance and retention were 73.9% and 88.5%, respectively. Implementing MEND 7–13 under service level conditions was associated with short-term improvements in anthropometric, fitness and psychological indices in a large sample of low-income, ethnically diverse children with overweight and obesity. A peer effect was quantified showing that benefits for an individual child were enhanced, if peers in the same group also performed well. To our knowledge, this is the first US study to evaluate outcomes of an up-scaled community-based, child weight management program and to show positive peer effects associated with participation in the intervention.