Too much TV ups obesity and diabetes risk in women

NEW YORK (Reuters Health) - Women who are glued to the boob-tube are also likely to watch their waistlines expand, Harvard researchers reported Tuesday.

What's more, some of these women may go on to develop type 2 diabetes, according to their report, published in the April 9th issue of the Journal of the American Medical Association

"This study emphasizes the importance of reducing prolonged TV watching and other sedentary behaviors for preventing obesity and diabetes," write Dr. Frank B. Hu and colleagues at Harvard University and Brigham and Women's Hospital in Boston.

The rate of obesity among U.S. adults has increased by 74 percent since 1991, according to a recent report from the Centers for Disease Control and Prevention (CDC). Extremely obese people have a seven-fold greater risk of diabetes, according to the CDC report, and are more likely to have high blood pressure and arthritis than people with normal body weights.

In the current study, Hu's team looked at more than 50,000 women participating in the Nurses' Health Study, a long-running project begun in 1976 to follow the health of female nurses across the U.S.

The researchers tracked the new cases of obesity and type 2 diabetes over six years, from 1992 to 1998.

By the end of this period, 3,757 women (7.5 percent) had become obese, and more than 1,500 had developed type 2 diabetes.

After accounting for exercise, diet, smoking and age -- factors that sway the risk of obesity and diabetes -- Hu's team found that each two-hour-per-day increment of TV watching was associated with a 23 percent increase in obesity risk and a 14 percent increase in diabetes risk.

"Our data provide strong evidence that sedentary behaviors, especially prolonged TV watching, are directly related to obesity and diabetes risk," the researchers conclude.

Obesity and type 2 diabetes are preventable, the authors point out.

Currently, the CDC recommends that people wishing to maintain good health schedule 30 minutes of moderate physical activity each day, and 60 minutes each day if they want to lose weight.