Association of dairy intake with weight change in adolescents undergoing obesity treatment

Background The role of dairy products in obesity treatment for adolescents is unclear. The study purpose was to assess the association between dairy intake and changes in BMI z-score (zBMI) during adolescent obesity treatment. Methods Observational study nested within a randomized control trial. Linear mixed-effects regression models were adjusted for important non-lifestyle factors then further adjusted for dietary and physical activity variables. In total, 91 adolescents were studied. Results Each serving of total dairy (beta = -0.0054, P < 0.01), unflavored milk (beta = -0.012, P < 0.01), reduced fat (beta = -0.0078, P < 0.05), and low fat/fat-free products (beta = -0.0149, P < 0.01) was associated with a decrease in zBMI over 12 months. These associations were no longer significant after adjustment for other dietary and physical activity factors. Sugar-sweetened beverage intake was inversely associated with intake of total dairy (beta = -0.186, P = 0.001), unflavored milk (beta = -0.115, P = 0.003) and low fat/fat-free dairy (beta = -0.125, P = 0.001). Conclusions Intakes of total dairy, unflavored milk, reduced fat dairy and low fat/fat-free dairy products are associated with improved obesity treatment outcomes among adolescents. This could be due to co-occurring healthy lifestyle behaviors or to replacement of other food and beverages associated with obesity, such as sugar-sweetened beverages, by dairy products.