A healthier lifestyle may prevent the vast majority of cases of type 2 (adult-onset) diabetes. A large study published in The New England Journal of Medicine (September 13, 2001;345) examined more than 85,000 female nurses and found that over 90% of type 2 diabetes cases could be attributed to lifestyle factors, particularly diet, body weight, and physical activity.
Type 2 diabetes occurs when the body becomes resistant to insulin or does not use insulin effectively. This differs from type 1 diabetes, in which the body does not produce insulin. Type 2 diabetes is strongly associated with excess body weight.
In the study, the risk of diabetes increased steadily with weight gain. Even women whose weight fell at the higher end of the normal range had nearly a threefold increase in diabetes risk. In contrast, regular physical activity had a strong protective effect. Women who exercised seven or more hours per week reduced their risk of developing diabetes by approximately 50%.
