The Eat More, Weigh Less program emphasizes complex carbohydrates that are also rich in fiber, which helps people feel satiated. Fiber also slows the absorption of food so that blood sugar rises slowly, averting spikes.

Before you turn your nose up at this low-fat, vegetarian program because it sounds "too healthy," keep in mind that Dr. Ornish has teamed up with some of the finest chefs around to create recipes like chilled cucumber and dill soup, vegetable strudel and blueberry pancakes. There is no limit to how much you can eat, only a restriction for what you can eat.

People following the Eat More, Weigh Less diet should also focus on moderate exercise, stress reduction and smoking cessation to get the most out of the program. While many people are hard-pressed to find fault with Eat More, Weight Less, critics charge that the plan is hard-to-follow if you're not an avid vegetarian. There are also concerns that the diet is too low in fat and eliminates fish which are rich in essential fatty acids that prevent disease.