Weight change, initial weight status, and mortality among middle- and older-aged adults

Mikko Myrskylä, Max Planck Institute for Demographic Research
Virginia W. Chang, University of Pennsylvania

We study how the weight change-mortality relationship depends on initial weight status and the magnitude of weight change using the Health and Retirement Study. We find that among 50-70 year old Americans, large and small weight losses (3-5 and 1-2.9 BMI units) are associated with excess mortality unless initial BMI is above 32. For example, hazard ratio (HR) for large loss for BMI of 30 is 1.61 (95% CI: 1.31-1.98) and HR for small loss for BMI of 30 is 1.19 (95% CI: 1.06-1.28). Large gains are associated with excess mortality if initial BMI is above 35, and small gains are not associated with excess mortality in any initial BMI group. The inverse association between weight loss and mortality was robust to adjustments for health status and unobserved confounders. The results suggest that the potential benefits of a lower BMI are offset by the negative effects associated with weight loss.