Association of body weight change with all-cause and cause-specific mortality: A nationwide population-based study

Aims: Weight gain and loss increase the risk of all-cause mortality. This study explored the association of short-term weight change with all-cause and cause-specific mortality in middle-aged to older people. Methods: This was a 8.4-year retrospective cohort study of 645,260 adults aged 40 to 80 who underwent health checkups twice within a 2-year interval between January 2009 and December 2012. Cox analyses were used to analyze the association between short-term weight change and all-cause and cause-specific mortality. Results: Weight gain and loss were associated with an increased risk of all-cause mortality: the hazard ratios were 2.05 (95% confidence interval [CI], 1.93–2.16), 1.21 (95% CI, 1.16–1.25), 1.12 (95% CI 1.08–1.17), and 1.60 (95% CI, 1.49–1.70) for the severe weight loss, moderate weight loss, moderate weight gain, and severe weight gain groups, respectively. This U-shaped association was also seen between weight change and cause-specific mortality. Within the weight loss group, those who regained weight after two years had a reduced mortality risk. Conclusions: In a middle-aged and elderly population, weight gain or loss of more than 3% during a 2-year interval was related to an elevated risk of all-cause and cause-specific mortality.