To our knowledge, this is the first systematic review examining the
effects of diet-only and diet plus exercise interventions on change
in weight and metabolic risks in overweight and obese children and
adolescents. Based on the small number of short-term randomized
trials available, we found that diet plus resistance training led to a
greater gain inLBMand reduction in%BFcompared with diet alone.
Some evidence of achieving greater improvement in HDL-C, fasting
glucose, and fasting insulin levels by adding exercise training to
dietary interventionswas found, although diet-only interventionhad
a greater reduction in triglycerides levels immediately following intervention
and a greater reduction in LDL-C levels 1 year from baseline.
Findings on BMI change are consistent with a review37 of the
effects of resistance training onmetabolic outcomes inchildren that
found resistance training did not favorably affect BMI relative to notreatment
or diet-only controls. Our meta-analyses suggest that the
observed increase in BMI in the diet plus exercise group, especially
when resistance training was added, may be due to gain in LBM,
which is beneficial for long-term weight loss.This reiterates thatBMI
is a less sensitive indicator of body composition and weight change
in children and adolescents. Future dietary and exercise interventions
should consider including other outcome measures of adiposity,
such as %BF and LBM.