Middle-aged and elderly adults who gain or lose a moderate to large amount of weight—defined as a 10 percent change in weight—may have an increased risk of death, particularly from cardiovascular disease, a new study shows. Between them, weight loss was associated with higher risk than weight gain.
Furthermore, excessive weight loss increases risk among participants who were overweight or obese to start with, and excessive weight gain might increase risk even among participants with low or normal body mass index at baseline.
Researchers used data from 36,338 middle-aged and elderly Chinese Singaporeans who reported weight and height during interviews at both recruitment (1993-1998) and follow-up (1999-2004) surveys, and who had no history of cancer or cardiovascular disease.
Researchers computed weight change as the difference between weights at baseline and the follow-up surveys, after an average of six years. The researchers grouped weight loss into several categories: moderate-to-large weight loss (≥10 percent), small weight loss (5.1-9.9 percent), stable weight (±5 percent), small weight gain (5.1-9.9 percent), and moderate-to-large weight gain (≥10 percent). They used the Singapore Birth and Death Registry to follow participants for mortality.
“This first study on a large population-based cohort of Singaporean Chinese aligns with findings from similar studies conducted among European, Japanese, and Korean populations,” says Koh Woon Puay, professor at Duke-NUS Medical School and the Saw Swee Hock School of Public Health.
“The findings suggest that moderate-to-large weight change in mid-life and older age should be monitored closely by health practitioners, and weight loss, especially, should be considered critically in elderly individuals as it may be related to loss of muscle mass, frailty, and poor control of chronic diseases.”
The researchers urge caution in the interpretation of the study results, highlighting that they did not examine information regarding whether the weight loss was intentional and if the weight loss was due to loss of fat or lean mass.
Nevertheless, the findings suggest that it is prudent to maintain stability in body weight within the non-obese range for middle-aged and elderly populations to reduce risk of mortality.
“The observational nature of our study means we cannot generalize our findings to potential interventions at this point,” Koh says. “Further studies are needed to understand the mechanisms underlying the association between weight change and mortality.”
The study appears in the International Journal of Obesity.