Associations between fruit juice and milk consumption and change in BMI in a large prospective cohort of US adolescents and preadolescents

Background There are concerns that fruit juice and milk contribute to childhood obesity. Objective Determine the relationship between fruit juice and milk intakes and body mass index (BMI) change among preadolescents/adolescents. Methods Participants aged 9 to 16 years old from the Growing Up Today Study II completed surveys including validated food frequency questionnaires in 2004, 2006 and 2008. The contributions of one serving of juice or milk to total energy intake and 2-year change in BMI were evaluated using multiple linear regression. Additional analyses were conducted with subgroups of juice (orange juice and other fruit juice) and milk (low fat and high fat). Missing values for BMI were imputed using a multiple imputation approach, after which data from 8173 participants and 13 717 2-year interval observations were analysed. Results Baseline fruit juice consumption was inversely associated with BMI change in girls (beta = -.102 kg/m(2), SE = 0.038, P value = .008) but not boys after controlling for race, age, baseline BMI, and baseline and 2-year changes in total energy intake and physical activity. Orange juice was inversely associated with BMI change among girls (beta = -.137 kg/m(2), SE = 0.053, P value = .010) while other fruit juice, low fat and high fat milk were not associated with BMI change. Conclusion Orange juice was inversely associated with 2-year BMI change among preadolescent/adolescent girls but not boys and there were no significant associations with other juices or milk among either gender.