Effect of physical activity intervention on weight change in rural older Chinese: a cluster randomized controlled trial.

Background: Current randomized trial evidence for the effects of physical activity intervention on weight change in adults was mainly from western countries, with little reliable evidence from low- and middle-income countries, such as China, where lifestyle factors and obesity patterns differ substantially from those in western countries. We examined the effects of physical activity intervention on weight change using cluster randomized trial data among Chinese older adults.

Methods: The cluster randomized controlled trial included an 8-week physical activity intervention period and was followed up to 24 months. Eight villages were randomly assigned to the intervention group (4 villages, n = 240) or the control group (4 villages, n = 268). The intervention group received physical activity intervention based on the socio-ecological model, while the control group did not. The intervention involved three levels: individual, interpersonal, and community levels, which aimed to promote leisure-time physical activity of participants. The primary outcome of the present study was the difference in percentage weight change at 24 months from baseline. We used Tanita BC-601 analyzer scales to measure weight and recorded it to the nearest 0.1 kg.

Results: Among the 508 participants, the mean age was 70.93 (SD, 5.69) years, and 55.5% were female. There were significant differences in percentage weight change between the intervention group and the control group with a mean change of -1.78% (95% CI, -2.67% to -0.90%; p < 0.001) in the total sample, -1.94% (95% CI, -3.14% to -0.73%; p = 0.002) in participants with overweight/obesity, and -1.45% (95% CI, -2.73% to -0.18%; p = 0.027) among participants with underweight/healthy weight in favor of the intervention group at 24 months.

Conclusions: Physical activity intervention resulted in weight loss in rural older sample at 24 months. This suggested that physical activity interventions are feasible for weight loss among older adults, especially for those with overweight/obesity or aged under 80.

Trial registration: The study has been registered on the Chinese Clinical Trial Registry on April 20, 2021 (ChiCTR2100045653), https://www.chictr.org.cn/showproj.html?proj=123704 .