Benefits of Weight Loss

If overweight increases the risk of mortality, then we would anticipate that intentional weight loss would reduce it. A definitive demonstration of this prediction is not available, but several studies suggest that intentional weight loss does reduce risk. Weight loss maintained for 2 yr reduces blood pressure, improves abnormal lipid levels, and reduces the risk of diabetes . In the American Cancer Society study of women aged 40-64 yr who intentionally lost weight, there was a significant reduction in all cause mortality of 20-25%. Using the National Health Interview Survey with a 9-yr follow-up, intentional weight loss lowers mortality rate (Hazard Rate Ratio) by 24% .

Weight loss affects a number of risk factors. The data from participants in the Swedish Obesity Study show the degree of weight loss for individual risk factors. Changes in blood pressure and triglycerides are very responsive to weight loss, decreasing after a 5-10% weight loss. HDL cholesterol increases with a similar weight-related change. Total cholesterol, on the other hand, does not show a sustained effect until weight loss exceeds 20%. For most comorbidities, however, a 10% weight loss is sufficient to see significant improvement in risk factors. However, blood pressure returns to baseline by 4-6 yr even when weight loss is maintained .

Recent studies buttress the idea that losing about 5% of body weight can significantly reduce the risk of developing type 2 diabetes in high-risk individuals. In studies from Finland and the United States, conversion rates from impaired glucose tolerance to diabetes were reduced by 58%.