To examine the relation between weight change and weight fluctuation (cycling) and mortality in middle-aged men.
A prospective study of 5608 men aged 40 to 59 years at screening, drawn from one general practice in each of 24 British towns. Changes in weight observed during a 12- to 14-year period were related to mortality during the subsequent 8 years.
There were 943 deaths from all causes: 458 cardiovascular disease (CVD) and 485 non-CVD deaths. Those with stable weight or weight gain had the lowest total, CVD, and non-CVD mortality. Sustained weight loss or weight fluctuation (loss-gain or gain-loss) showed a significantly higher mortality risk than stable weight even after adjustment for lifestyle variables (relative risk [95% confidence interval], 1.60 [1.32-1.95], 1.50 [1.17-1.91], and 1.63 [1.24-2.14], respectively). Adjustment or exclusion of men with preexisting disease markedly attenuated the increased risk of CVD and total mortality associated with sustained weight loss and weight gain–weight loss. In long-term nonsmokers, any weight loss since screening was associated with an increased risk of mortality, but this was markedly attenuated by adjustment for preexisting disease. Recent ex-smokers showed the most marked increase in mortality associated with sustained weight loss.
The increased mortality in middle-aged men with sustained weight loss and weight fluctuation (cycling) is determined to a major extent by disadvantageous lifestyle factors and preexisting disease. The evidence suggests that weight loss and weight fluctuation (cycling) in these men does not directly increase the risk of death.