Exercise Not Enough to Offset Obesity Health Risks

Regular exercise is not enough to offset the health problems associated with obesity — but that shouldn’t stop people who are overweight from working out, according to a study to be published in Thursday’s New England Journal of Medicine.

Two-thirds of Americans are classified as overweight or obese. Being obese triples the risk of heart disease and produces a tenfold increase in the likelihood of developing diabetes.In recent years, some doctors have suggested that getting regular exercise may eliminate much of the risk of being fat. But the study in this week’s Journal, which followed more than 116,000 female nurses for 24 years, challenged that belief.Frank Hu of the Harvard School of Public Health and his colleagues found that a high level of physical activity did not eliminate the risk of premature death associated with obesity — and leanness did not offset the increased risk in mortality conferred by inactivity.Lean women who exercised less than 3-1/2 hours per week increased their risk of early death by 55 percent compared to women who worked out more frequently, the researchers found.Among obese women who worked out for at least 3-1/2 hours weekly, the death rate was 91 percent higher than in lean women who exercised for 3-1/2 hours weekly. And for inactive, obese women, the premature death rate was 142 percent greater.A 5’2″ woman was considered lean if she weighed less than 134 pounds and obese if she weighed over 160 pounds.Hu said even though it appeared that exercise did not entirely counteract the health risks of obesity, it was clear that both weight and exercise are key to longevity.”If you are overweight or obese, exercise is good for you even if you don’t lose weight,” Hu told Reuters. “For people who are lean and sedentary, it’s really important for them to get out of the couch and exercise, even if they don’t have to lose weight.”The findings probably applied to men as well, he added.The Hu team estimated that not being lean and not getting enough exercise could account for 31 percent of all premature deaths, 59 percent of deaths from cardiovascular disease, and 21 percent of deaths from cancer among women who do not smoke.A second study in this week’s Journal suggested that the benefits of stomach surgery — designed to help people lose weight — persist for 10 years or longer,More than 100,000 such surgeries are done in the United States each year. The new research, led by Lars Sjostrom of the Sahlgrenska University Hospital in Goteborg, is the first long-term assessment of the outcome.After two years, 23 percent of the 1,845 patients who received a stomach operation weighed less; the average weight among 1,660 in the control group had not changed. After 10 years, 16 percent of the surgery recipients had kept the weight off, while nearly 2 percent of the people in the control group had gained pounds.But the impact registered beyond the bathroom scale.Thirty-six percent of the surgery recipients who had diabetes before the operation were no longer diabetic, compared with 13 percent of the volunteers in the control group.And while 24 percent who didn’t have surgery developed diabetes over the following decade, the rate was 7 percent for the stomach surgery recipients.Journal editors Caren Solomon and Robert Dluhy cautioned that it is not known whether the benefits translate into reduced rates of heart attack and stroke. (Source: New England Journal of Medicine, Reuters Health, December 2004)