Health benefits and risks of eating a low-fat, high-fiber diet

The Journal of the American Medical Association recently published a large trial looking at health benefits and risks of eating a low-fat, high-fiber diet in 48,000 postmenopausal women. The women were followed for an average of 7.5 years. The results showed that the women who ate diets higher in carbohydrates including fiber lost weight and kept it off compared to women who were given no specific dietary advice.

This study provides further impressive evidence that carbohydrates are not all bad, and supports findings in numerous studies that diets that are high in fruits and vegetables are associated with significant health benefits. Most importantly, it should put to rest the notion that a high-carbohydrate, low-fat eating pattern causes weight gain, increased triglycerides, or increases the risk of diabetes.

"Weight loss was greatest among women in either group who decreased their percentage of energy from fat,” according to the article. Women who consumed a low-fat, high-fiber diet lost an average of 4.8 pounds in the first year, and kept the weight off better than the control group.

The study showed a 9% lower risk of developing breast cancer in the low-fat, high-fiber group, although this finding did not reach statistical significance. In other words, there appeared to be a trend, but it could have been coincidence. Although 7 years is a fairly long medical study, longer studies are needed to fully evaluate these interventions.

Women were not counseled about the type of fats to avoid, so there is no surprise that there were no differences noted in the rate of cardiovascular events (heart disease, stroke). A diet high in omega 3 polyunsaturated fats and monounsaturated fats, from sources such as fish, nuts, and many vegetable oils, and low in saturated and trans fats, found in animal sources and partially hydrogenated oils appears to lower the risk of cardiovascular disease.

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