Exercise and adiposity in overweight and obese children and adolescents: a systematic review with network meta-analysis of randomised trials

OBJECTIVES: Determine both the effects and hierarchy of effectiveness for exercise interventions (aerobic, strength training or both) on selected measures of adiposity (body mass index (BMI) in kg/m(2), fat mass and per cent body fat) in overweight and obese children and adolescents. DESIGN: Network meta-analysis of randomised exercise intervention trials. SETTING: Any setting where a randomised trial could be conducted. PARTICIPANTS: Overweight and obese male and/or female children and adolescents 2–18 years of age. INTERVENTIONS: Randomised exercise intervention trials>4 weeks, published between 1 January 1973 and 22 August 2018, and which included direct and/or indirect evidence for aerobic, strength training or combined aerobic and strength training. PRIMARY OUTCOMES: Changes in BMI in kg/m(2), fat mass and per cent body fat. RESULTS: Fifty-seven studies representing 127 groups (73 exercise, 54 control) and 2792 participants (1667 exercise, 1125 control) met the criteria for inclusion. Length of training ([Formula: see text] ± SD) averaged 14.1±6.2 weeks, frequency, 3.3±1.1 days per week and duration 42.0±21.0 min per session. Significant and clinically important reductions in BMI, fat mass and per cent body fat were observed in aerobic versus control comparisons (BMI, mean, 95% CI -1.0, 1.4 to −0.6; fat mass -2.1, –3.3 to −1.0 kg; per cent fat -1.5, –2.2 to −0.9%) and combined aerobic and strength versus control comparisons (BMI -0.7, –1.4 to −0.1; fat mass -2.5, –4.1 to −1.0 kg; per cent fat, -2.2, –3.2 to −1.2%). A significant reduction in per cent fat was also found for strength vs control comparisons (-1.3,–2.5 to −0.1%). Combined aerobic and strength training was ranked first for improving both fat mass (kg) and per cent body fat while aerobic exercise was ranked first for improving BMI. CONCLUSIONS: Aerobic and combined aerobic and strength training are associated with improvements in adiposity outcomes in overweight and obese children and adolescents. PROSPERO REGISTRATION NUMBER: CRD42017073103.