Effects of weight loss on psychological variables in combat sports athletes: a systematic review

PurposeTo analyze the effects of weight loss on psychological variables in combat sports athletes.MethodsElectronic searches were performed to find studies that investigated the psychological acute effects resulting from weight loss in combat sports athletes. Cochrane Library, PsycINFO, PubMed, Scopus, SPORTDiscus, and Web of Science databases were searched from inception to December, 2024. The quality assessment was conducted through the application of the RoBANS tool.ResultsOf the 1,602 articles retrieved in the electronic search and identified through other sources, 22 met the inclusion criteria. A total of 784 athletes (men: 557; women: 115; not reported/specified: 112) were investigated. The main results of the included studies reported deleterious effects of weight loss on mood states, as well as higher depression scores among athletes who lost weight. However, no differences for levels of burnout were verified after the weight loss. In addition, the effects of the loss seem to be influenced by the magnitude of the loss.ConclusionWeight loss appears to have negative psychological effects in combat sport athletes, especially on mood and depression levels. However, most studies present limitations that lead to important biases in the interpretation of the results. PROSPERO register number: CRD42023394712.