Energy cost of walking and body composition changes during a 9-month multidisciplinary weight reduction program and 4-month follow-up in adolescents with obesity

The purpose of the present study was to investigate changes in the energy cost of locomotion during walking (Cw) related to the changes in body mass (BM, kg) and body composition in adolescents with obesity. Twenty-six (12 boys and 14 girls) obese adolescents (mean: BMI, 33.6±3.7 kg/m2; 42.7±4.5 % fat mass) followed a 9-month multidisciplinary inpatient weight-reduction program consisting of lifestyle education, moderate energy restriction, and regular physical activity in a specialized institution. At baseline (M0), by the end of the 9-month program (M9) and after 4-months follow-up (M13), V'O2 and V'CO2 of standardized activity program were assessed by whole-body indirect calorimetry over 24 hours, and body composition was assessed by DXA. At M9, adolescents showed a 18% reduction in BM (p<0.001), 40% in total FM; while FFM (kg) remained stable in boys but decreased by ~6% in girls (p=0.001). Similarly, the mean Cw decreased by 20% (p<0.001). At M13, BM, FM and Cw were slightly higher compared than at M9. In conclusion, moderate energy restriction and regular moderate physical activities improved walking economy, improved exercise tolerance and induced beneficial changes in body composition of adolescents with obesity. Novelty bullets • Reduction of FM in the trunk region, and consequently reducing the work carried out by respiratory muscles, contribute to reduce Cw in adolescents with obesity. • A lower cost of walking can be effective in improving exercise tolerance and quality of life in obese adolescents.