Increases in physical activity reduces BMI gain in Mexican obese girls attending elementary school

Abstract

BackgroundIn México the prevalence of unhealthy weight jumps from 5% at 5 y to 25% at 7 y, making this a window of opportunity to better understand the pathogenesis of obesity.ObjectiveTo explore the association between PA patterns and obesity over the transition from kindergarten (K) to elementary school (ES) in a cohort of Mexican children.MethodsThe PA (5‐d accelerometry) and BMI of 211 children (5–6 y at the beginning of the study) were measured while in K, 1st and 2nd grade of ES. Associations between PA changes and BMI changes were examined using multiple, longitudinal regression models stratified by sex, controlling for energy intake and other demographic variables.ResultsOverweight/obese girls who had increased their PA level from 1st to 2nd grade ES had a lower BMI gain compared to obese girls who decreased or maintained their PA (0.02 kg/m2, 95%CI: −1.8, 1.9 vs 2.8 kg/m2, 95%CI: 2.2, 3.3, respectively). This association was not observed comparing changes from K to 1st or 2nd grade ES. In boys, changes in PA were not associated with change in BMI.ConclusionIn obese girls, an increase in PA in the early years of ES may result in decreased adiposity overtime.