Objective: To estimate the effect of weight-loss interventions on health-related quality of life (HrQoL) in randomized controlled trials (RCTs); to conduct a meta-analysis of weight-loss treatment on depressive symptoms; and, to examine methodological and presentation issues that compromise study validity.
Study design and setting: We conducted a structured review of 34 RCTs with weight-loss interventions that reported the relationship between HrQoL and treatment at two or more time points. We also evaluated study quality.
Results: Trials lasted 6 weeks to 208 weeks and evaluated behavioral, surgical, or pharmacologic interventions. Nine of 34 trials showed HrQoL improvements in generic measures. Obesity-specific measures were more likely to show improvement in response to treatment than non-obesity-specific measures. Meta-analysis showed no treatment effect on depressive symptoms. Most trials tracked loss to follow-up and conducted intent-to-treat analysis, but only four trials concealed recruitment staff to randomization and 14 blinded the investigation team to randomization.
Conclusion: HrQoL outcomes, including depression, were not consistently improved in RCTs of weight loss. The overall quality of these clinical trials was poor. Better-designed RCTs using standardized HrQoL measures are needed to determine the extent to which weight loss improves HrQoL.