A total of 38 studies were included in this review (n=unclear): 23 studies from the previous study and an additional 15 studies.
There was insufficient evidence to assess the effectiveness of dietary interventions versus control (three studies, n=989). School-based physical activity interventions were reported to be significantly more effective than a control intervention in five (n=approximately 1,103) out of 15 studies (n=approximately 6,609) according to mean BMI change. Two of the five studies with significant results reported significant differences for girls but not for boys (n=391).
Overall the effects were inconsistent and short term.
Diet and physical activity interventions were compared with a control in 20 studies, of which nine reported significant improvements in mean BMI for the intervention groups. Overall effectiveness of these combined interventions was equivocal.
Process evaluations were either not reported or reported poorly in the included studies.