BACKGROUND: The speeding increase and the high prevalence of childhood obesity is a serious problem for Public Health. Community Based Interventions has been developed to combat against the childhood obesity epidemic. However little is known on the efficacy of these programs. Therefore, there is an urgent need to determine the effect of community based intervention on changes in lifestyle and surrogate measures of adiposity. METHODS/DESIGN: Parallel intervention study including two thousand 2249 children aged 8 to 10 years ( 4th and 5th grade of elementary school) from 4 Spanish towns. The THAO-Child Health Program, a community based intervention, were implemented in 2 towns. Body weight, height, and waist circumferences were measured. Children recorded their dietary intake on a computer-based 24h recall. All children also completed validated computer based questionnaires to estimate physical activity, diet quality, eating behaviors, and quality of life and sleep. Additionally, parental diet quality and physical activity were assessed by validated questionnaires. DISCUSSION: This study will provide insight in the efficacy of the THAO-Child Health Program to promote a healthy lifestyle. Additionally it will evaluate if lifestyle changes are accompanied by favorable weight management. TRIAL REGISTRATION: Trial Registration Number ISRCTN68403446.

This work was supported by grants from Instituto de Salud Carlos III FEDER, (PI11/01900) and by a joint contract (CES09/030) with the Instituto de Salud Carlos III and the Health Department of the Catalan Government (Generalitat de Catalunya)