The diet and diabetes dilemma

Drinking more sugar-sweetened beverages or eating fewer fruits and vegetables both may be associated with an increased risk of type 2 diabetes, whereas eating a low-fat diet does not appear to be associated with any change in diabetes risk, according to three reports in the July 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

Diabetes rates continue to increase, particularly in developed countries, according to background information in the articles. By the year 2030, 11.2 percent of U.S. adults are expected to have the condition. Obesity is the strongest modifiable risk factor for the development of type 2 diabetes.

In one of the reports, Dr. Lesley Tinker, of the Women’s Health Initiative, and colleagues studied the effects of eating a low-fat diet on diabetes risk in 48,835 postmenopausal women. From 1993 to 2005, 29,294 of the women were randomly assigned to continue eating their usual diet while 19,541 were given a low-fat (20 percent of calories from fat) diet with increased levels of fruits, vegetables and whole grains. The diet was not intended to help participants lose weight.

The researchers found that modest weight loss, rather than macronutrient composition, may be the dominant predictor of reduced risk of diabetes. The beauty of a low-fat diet that includes lots of vegetables and fruits is that it is sustainable, Tinker said. After an average of seven years of follow-up, participants in the low-fat dietary change intervention group maintained a significantly lower fat intake and minor weight loss than did participants in the usual diet comparison group.

"Women in the low-fat group lost about 1.9 kilograms or 4.2 pounds after the first year and maintained a lower weight by one pound after 7.5 years of follow-up compared to women in the usual diet group," Tinker said. "Although the risk of developing diabetes didn't decrease overall, neither did risk increase, thus supporting low-fat dietary eating style as an option for postmenopausal women who are concerned about developing diabetes."

Of the take-home message, Tinker said, "A low-fat dietary pattern that includes lots of vegetables and fruits may be a viable option for postmenopausal women who are concerned about developing diabetes."