August 15, 1997

Media Contacts: Sarah Goodwin, 404/727-3366 -
Kathi Ovnic, 404/727-9371 -

No, 40:30:30 isn't referring to someone's measurements; it's the latest diet craze. Once again, entrepreneurs are cashing in on Americans' desperation for thinness. The newest pop wisdom advocates a high-protein, low-carbohydrate diet (40 percent carbohydrate: 30 percent protein: 30 percent fat) which also happens to be very low in calories.

True, Americans are getting heavier despite the fact that more low-fat and no-fat foods are available than ever before. So what is causing this paradox? Could carbohydrates, not fat, be to blame for our bulging waistlines?

The answer could lie in the simple calorie, says Emory Heart Center's Nancy Anderson, M.P.H., R.D., Coordinator of the Emory HeartWise Program.

"Even though many people are consuming lower fat foods, they are not necessarily cutting calories," Ms Anderson says. "A calorie is a calorie is a calorie, no matter if it comes from fat, protein or carbohydrate. If you take in more calories than you burn off, you're going to gain weight."

Anti-carbohydrate advocates tend to rely on anecdotes rather than clinical trials to make their claims, Ms. Anderson says. Claims that carbohydrates, found in foods such as pasta, breads, and cereals, signal the body to overproduce insulin -- and store fat -- are not substantiated by endocrinologists, says Emory cardiologist Paul Robinson, M.D., medical director of the U.S. 10K Classic and an avid marathoner.

Athletes, especially those looking for a competitive edge, may be lured by promises of rapid weight loss and increased energy. Some athletes report great success with such diets, while others report that going low-carbohydrate and high-protein does not work for them at all. This variability, according to nutrition experts, may be attributed to the types of diets athletes maintained before making the change. For instance, if a person eats a very-high-carbohydrate (more than 75 percent of calories) and very-low-fat diet based on bagels and pasta, they may actually feel better when they eat a diet with more protein, calcium, iron and zinc. Also, because very-low-calorie diets can leave you feeling hungry, increasing fat intake adds satiety, thus reducing the urge to snack. The result: a diet with a moderate amount of fat can be more satisfying, helping you consume fewer calories.

Many other active people find the new diets too restrictive and too cumbersome since they tend to restrict calorie intake and may require careful weighing and measuring of foods to conform to the rigid 40:30:30 ratio.

"Consuming too few calories leaves a person feeling sluggish and tired," Ms. Anderson says. "Instead of improving athletic performance, a low-carbohydrate, low-calorie diet can leave you without the energy needed to train or compete. Watch out for fad diets. Your best bet is to eat a balanced, low-fat diet consisting of 20 to 30 percent of calories from fat, 55 to 65 percent of calories from carbohydrate, and the remaining calories from protein," she says.

For more general information on The Robert W. Woodruff Health Sciences Center, call Health Sciences News and Information at 404-727-5686, or send e-mail to

Copyright ©Emory University, 1997. All Rights Reserved.
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