Effect and safety of a physical exercise-based intervention on body composition and cardiometabolic health of adolescents with severe obesity. Secondary analysis from the PAC-MAnO trial

Severe obesity (SOb) treatment in adolescents has been focused on surgery and pharmacological treatment, in part due to difficulty in implementing lifestyle behavioral changes, such as physical exercise. However, the potential long-term consequences and costs of these options prompt new effective and sustainable treatment options. This study aimed to investigate the effect and safety of a 6-month high-intensity physical exercise-based intervention on body composition and cardiometabolic health in adolescents with SOb (BMI z-score ≥ 3), compared to those without SOb and SOb controls (without intervention). Data from 46 adolescents (50% girls), including 20 with SOb (43.5%), exposed to two exercise sessions/week for 6 months, and 16 controls were analyzed. Adolescents with SOb showed a higher decrease and increase in central fat mass ( β= -2.3, 95%CI: 4.8, 0.1) and fat-and-bone-free mass ( β =1.70, 95%CI: 3.25, 0.15) and a higher rate of insulin resistance normalization (58.3 vs. 12.5%) after the intervention, compared to those without SOb, with no differences in adverse effects. Adolescents with SOb exposed to intervention also showed improvements in BMI, compared to an impairment in controls (95%CI: -2.64, 0.16). High-intensity physical exercise-based interventions should be considered as an obesity treatment option in adolescents with SOb. Higher exercise volume and/or frequency may further improve health-related outcomes and should become a first-line strategy alongside other lifestyle changes. Clinicaltrials.gov NCT02941770 • A 6-month high-intensity exercise program improved body composition and insulin resistance in adolescents with severe obesity (SOb). • Adolescents with SOb responded equally or more favorably than no-SOb, without serious adverse effects. • Consistent attendance (≥80% of sessions) was associated with greater improvements, emphasizing the importance of adherence.