Combined Effects of Physical Activity and Diet on Cancer Patients: A Systematic Review and Meta-Analysis

Background: The purpose of our systematic review was to examine the effects of any physical activity/exercise intervention combined with any diet/nutrition intervention on any biological/biochemical index, quality of life (QoL), and depression in breast, lung, colon and rectum, prostate, stomach, and liver cancer patients and/or cancer survivors. Methods: A systematic review and meta-analysis were undertaken, using PRISMA guidelines and the Cochrane Handbook. The systematic review protocol can be found in the PROSPERO database; registration number: CRD42023481429. Results: We found moderate-quality evidence that a combined intervention of physical activity/exercise and nutrition/diet reduced body mass index, body weight, fat mass, insulin, homeostatic model assessment for insulin resistance, C-reactive protein, triglycerides, and depression, while it increased high-density lipoprotein, the physical component of QoL, and general functional assessment of cancer therapy. Conclusions: We conclude that a combined intervention of physical activity/exercise and diet/nutrition may decrease body weight, fat mass, insulin levels, and inflammation, and improve lipidemic profile, the physical component of QoL, and depression in cancer patients and survivors. These outcomes indicate a lower risk for carcinogenesis; however, their applicability depends on the heterogeneity of the population and interventions, as well as the potential medical treatment of cancer patients and survivors.