Can sustained weight loss in overweight individuals reduce the risk of diabetes mellitus?

Although rates of adult-onset diabetes mellitus increase with increasing ob esity, there is little evidence that weight loss in overweight individuals can reduce their risk of developing diabetes. Using data from the Framingha m Study, we examined the effects of sustained and nonsustained weight loss on risk of diabetes mellitus among 618 overweight (body mass index greater than or equal to 27) subjects 30-50 years of age. To separate sustained fro m nonsustained weight loss, we examined weight change in two consecutive 8- year periods. Subjects who had stable weight (+/1 lb per year) during both periods served as the referent group for all analyses. Sustained weight los s led to a 37% lower risk of diabetes [relative risk (RR) = 0.63; 95% confi dence interval = 0.34-1.2], and this effect was stronger for more obese (bo dy mass index greater than or equal to 29) subjects (RR = 0.38; 95% confide nce interval = 0.18-0.81). Those who lost 8.1-25 lb had a 33% reduction in diabetes risk, whereas those losing more had a 51% reduction in risk. Regar dless of the amount of weight lost, those who regained the lost weight had no reduction in diabetes risk (RR = 1.1 and 1.2 for those who lost 8.1-15 a nd >15 Ib, respectively). We conclude that a modest amount of sustained wei ght loss can substantially reduce the risk of diabetes mellitus in overweig ht individuals.