The effects of weight-lowering pharmacotherapies on physical activity, function and fitness: A systematic review and meta-analysis of randomized controlled trials

Weight-lowering pharmacotherapies provide an option for weight management; however, their effects on physical activity, function, and cardiorespiratory fitness are not fully understood. We conducted a systematic review and meta-analysis of randomized controlled trials to investigate the effect of licensed weight loss pharmacotherapies on physical activity, physical function, and cardiorespiratory fitness in individuals with obesity. Fourteen trials met our prespecified inclusion criteria: Five investigated liraglutide, four semaglutide, three naltrexone/bupropion, and two phentermine/topiramate. All 14 trials included a self-reported measure of physical function, with the pooled findings suggesting an improvement favoring the pharmacotherapy intervention groups (SMD: 0.27; 95% CI: 0.22 to 0.32) and effects generally consistent across different therapies. Results were also consistent when stratified by the two most commonly used measures: The Short-Form 36-Item Questionnaire (SF-36) (0.24; 0.17 to 0.32) and the Impact of Weight on Quality Of Life-Lite (IWQOL-Lite) (0.29; 0.23 to 0.35). Meta-regression confirmed a significant association between pharmacotherapy induced weight loss and improved physical function for IWQOL-Lite (p = 0.003). None of the studies reported a physical activity outcome, and only one study reported objectively measured cardiorespiratory fitness. Improvements in self-reported physical function were observed with weight loss therapy, but the effect on physical activity or objectively measured physical function and fitness could not be determined.