More than 10% of the global population suffers from obesity. There is enough evidence to establish an association between obesity and a higher risk of conditions like diabetes, cardiovascular diseases, and hypertension, but recent studies have also indicated a link between weight gain across adulthood and an increased risk of mortality. This study aims to evaluate the association between weight changes across adulthood and mortality.

This prospective cohort study included 36,051 participants aged 40 or more with measured body weight at baseline, young adulthood (25 years), and 10 years before. The primary outcome of the study was all-cause and cause-specific mortality.

10,500 deaths occurred during a mean follow-up of 12.3 years. The researchers found that participants moving from non-obese to obese categories between young and middle adulthood had a higher risk of all-cause and cause-specific mortality (especially heart-related). Changing from obese to non-obese was not associated with increased mortality, and maximum overweight had a null effect on mortality across adulthood. No significant associations were found between obesity and cancer-related deaths.

The research concluded that weight gain and maintaining obese weight across adulthood was associated with an increased risk of all-cause and cause-specific (heart-related) mortality.