Zone Diet
Proponents of the Zone diet recommend a diet consisting of lean proteins
and naturally occuring carbohydrates (like those found in high-fiber
vegetables and fruit.) The Zone diet recommends that you consume 40 percent
of your calories from carbohydrates,
30 percent from protein and 30 percent from fat (the so-called 40:30:30
proportions).
The Zone diet is said to work for two reasons:
- Adherents reduce their overall caloric intake;
- A dramatic reduction in caloric intake (because of fasting
or beginning a low-calorie diet) often causes your body to go
into "survival" mode. Your body will actually begin to conserve
energy and burn fewer calories while you rest. (Referred to
in the literature as a low
basal metabolic rate).
However, the 40:30:30 combination of food
proposed by the Zone diet prevents the body from thinking that
it has begun to starve, thus your basal rate does not decline.
Who created the Zone diet?
Dr. Barry Sears introduced the diet in his book Enter the Zone,
published in 1995.
Medical Studies
In a 2001 study, Dr. Donald Layman (University of Illinois, Urbana-Champlain)
placed 12 middle-aged overweight women on a 1660 calories per day diet
consistent with the USDA's Food Guide Pyramid. He placed 12 other middle-
aged overweight women on a 1660 calorie diet consistent with the Zone diet.
After 10 weeks, those on the Zone-equivalent diet lost slightly more
weight (16.5 vs 15 pounds) but the real story was in the makeup of the
weight loss. Those on the Zone-equivalent diet lost 27% less muscle and
18% more body fat than those following the USDA-equivalent diet. In
addition, the study reported evidence that the women on the Zone-equivalent
diet burned more calories while resting.
A 1999 study led by Dr. David Ludwig found that patients following a high-
carbohydrate diet (perhaps more accurately, a high
glycemic index diet) burned
fewer calories at rest than did those who followed a roughly Zone-
equivalent diet.
Additional Resources:
Enter the Zone, Barry Sears, MD. (1995)
