The effects of exercise with or without dietary advice on muscle mass, muscle strength, and physical functioning among older cancer survivors: a meta-analysis of randomized controlled trials

PURPOSE: To evaluate the effect of exercise with or without dietary advice on muscle mass, muscle strength and physical functioning (including perceived physical functioning and physical performance) in old cancer survivors. METHODS: A systematic literature search was undertaken in May 2022 by searching multiple databases. Randomized controlled trials (RCTs) that compared exercise with or without dietary advice to control group among old cancer survivors were screened. Meta-analyses were conducted to evaluate the effects of exercise with or without dietary advice on muscle mass, muscle strength, and physical functioning. RESULTS: Data from 21 trials were included in this study, including 16 exercise trials and 5 exercise + dietary advice studies. Regarding exercise, evidence supported its significant benefits on muscle strength among old cancer survivors, while no effect was seen on physical functioning and muscle mass. Concerning exercise combined with dietary advice, meta-analysis showed overall benefits on physical functioning, while limited study examined muscle mass and strength. As for safety and feasibility of interventions, low recruitment rate, moderate compliance, and few adverse events were reported. CONCLUSIONS: Exercise combined with dietary advice is a more effective approach for old cancer survivors in improving physical functioning compared with exercise alone. Future study is needed to explore the effects of exercise combined with dietary advice on combating sarcopenia. As recruitment and compliance among old cancer survivors were challenging, strategies to stimulate their motivation and promote habitual healthy behaviour are warranted. IMPLICATIONS FOR CANCER SURVIVORS: It is necessary for old cancer survivors to receive exercise and dietary support to improve physical functioning. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11764-023-01396-z.