Dietary content and combined training, but not daily physical activity, are associated with 6-month bone mineral changes in adolescents with obesity: A Secondary analysis of the PAC-MAnO trial

The present study aimed to explore the influence of diet and physical activity (PA) changes on bone mineral content (BMC) and density (BMD) alterations in adolescents with obesity undergoing a weight loss program.

Six-month longitudinal data from 71 adolescents (aged 15.1 [± 1.6] years; 57.7% girls) with a BMI z-score of 3.03 (± 0.78), previously recruited for the PAC-MAnO trial, were analyzed using Generalized Estimation Equations for over time changes and linear regressions with BMC, BMD and BMD z-score as dependent variables, adjusting for confounders (including type of exercise- aerobic vs. combined).

Adjusting for confounders, changes in carbohydrate (CH) and protein content showed to positively and negatively predict BMD z-score variance, respectively (β = 0.44, 95%CI: 0.01, 0.04, p < .001); β = -0.57, 95%CI: -0.06, -0.03, p < .001), yet no associations were found between PA and bone-related parameters. Combined exercise showed better results on BMC compared to aerobic exercise (β = 0.09, 95%CI: 0.05 to 0.13, p < .001).

Increased CH content, instead of protein, may be associated with BMD improvements in adolescents with obesity. Type of exercise may moderate the impact of PA on bone health.

Clinicaltrials.gov NCT02941770.