Six trials were included in the review (n=407). Dropout was less than 20% in all trials except one. No study gave information on blinding or intention-to-treat analysis. Two described the randomisation process.
Post-intervention: Mean weight loss in the diet and exercise groups was 13kg compared to 9.9kg in the the diet-only group, but this result was not statistically significant. Results remained the same when one study with a drop-out rate greater than 20% was removed.
One-year follow-up: Mean weight loss in the diet and exercise groups was 6.7kg compared to 4.5kg in the diet-only groups, but this result was not statistically significant. Removal of the study with over 20% drop-out resulted in a statistically significant difference in favour of diet and exercise (p=0.03).