A Warning on High-Protein Diets

High-protein diets--such as the popular Atkins, Zone, Power Protein, Sugar Busters and Stillman diets--have not been proved to promote weight loss and may even be dangerous for those who adhere to them for more than a short time, the American Heart Assn. warned in an advisory last week.

The advisory, from the association’s Nutrition Committee, was issued to counter “quick weight-loss” regimens that attract so many followers in the United States.

According to the committee, many high-protein diets are high in fat and low in nutritionally rich foods, such as fruits and vegetables. Some of the diets also fail to provide for essential vitamins and minerals and fiber, said Dr. Robert H. Eckel, a co-author of the advisory.

High-protein diets have not been documented to deliver on their promise of sustained, long-term weight loss, he said. People may believe they are losing weight because high-protein diets can trigger a loss of body fluids by eliminating most carbohydrates. But that kind of weight loss is not permanent.

“It’s important for the public to understand that no scientific evidence supports the claim that high-protein diets enable people to maintain their initial weight loss,” Eckel said. “In general, quick weight-loss diets don’t work for most people.”

Moreover, high-protein diets often emphasize meat and eggs, foods that are rich in protein and saturated fat.

Eating large amounts of high-fat animal foods over a sustained period has been shown to increase the risk of coronary artery disease, diabetes, stroke and some types of cancer.

For people with kidney or liver disease, unneeded protein may even worsen their disease, the advisory states. Most Americans already eat more protein than their bodies need, Eckel said.

Besides the detrimental effects of too much protein, the diets can cause problems by limiting carbohydrate intake, the advisory stated. Lean muscle tissue is often lost when carbohydrate intake drops below a certain threshold. Fatigue is also a result of not getting enough carbohydrates.

According to Eckel, individuals who want to lose weight are best served by adopting a diet that has been shown to be safe and promotes sustained weight loss, such as the diet described in the American Heart Assn.’s nutritional guidelines. Weight loss is most effective when combined with an exercise program, he added.

The advisory is published in the new issue of Circulation: Journal of the American Heart Assn.