Carbs May Not Weigh You Down
Women's Study Suggests That a Low-Fat Diet Doesn't Add Pounds
By JENNIFER CORBETT DOOREN
DOW JONES NEWSWIRES
January 4, 2006; Page D5
WASHINGTON -- Diets low in fat and high in carbohydrates from fruits, vegetables and whole grains didn't lead to weight gain during a seven-year period, according to a large study of postmenopausal women.
The study involved more than 48,000 women who are part of a larger, federally funded study known as the Women's Health Initiative, in which researchers are looking at ways to prevent heart disease, osteoporosis and breast and colon cancer in women.
One of the initiatives involves looking at whether a low-fat diet helps prevent heart disease and some cancers.
While the first of those results won't be out until later this year, researchers decided to look at the effect of the diet on women's weight during a time when popular diets such as Atkins advocated diets with a higher proportion of fats and fewer carbohydrates. The results are being published in today's Journal of the American Medical Association. The study was funded by a unit of National Institutes of Health.
The lead study author, Barbara V. Howard, president of the MedStar Research Institute in Washington, said some advocates of the Atkins diet and other low-carbohydrate diets had suggested that low-fat diets advocated by cancer and heart-disease prevention groups might be part of the reason behind the growing number of overweight Americans.
Ms. Howard said the low-fat diet in the Women's Health Initiative wasn't designed as a weight-loss tool. Several smaller studies have suggested that a low-fat diet cuts risks for heart disease, diabetes and some types of cancer.
The low-fat study looked at 48,835 postmenopausal women who were enrolled in the study from 1993 to 1998. The women were followed for an average of 7.5 years each through Aug. 31, 2004. Women who reported eating less than 32% of their total calories from fat weren't allowed to participate in the study. About 40% of the women in the study were assigned to a low-fat diet and about 60% of the women were in the so-called control group in which they ate a normal diet.
Women in the low-fat diet group were told to eat no more than about 20% of their total calories daily in fat. The other women weren't instructed specifically how to eat but were given educational materials about a healthy diet. Neither group was required to exercise or told to restrict their total calories to a certain level.
Researchers found that overall, after the first year of the study, women in the low-fat group lost an average of 4.8 pounds compared with women who followed their normal eating pattern. Many of the women maintained much of that weight loss over the next several years. Some regained the weight but didn't surpass the weight at which they entered the study, Ms. Howard said. Women in the low-fat group typically showed more sustained weight loss than those in the regular-diet group when they were weighed annually during the study.
Ms. Howard said results suggest that a low-fat diet may ward off the tendency for women to gain weight from their 40s through 60s. "Overall, this large randomized trial demonstrates that the dietary recommendations for reducing fat and replacing it with vegetables, fruits and grains don't increase body weight, which implies that guidelines that restrict fat intake and advocate increases in complex carbohydrates haven't been a contributing factor to the weight gain that has been occurring in the United States throughout the past several decades," the researchers wrote.
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