The diet largely consists of low-fat, high-fiber carbohydrates that are 400 calories or less per pound. There is a ratio of 75 percent carbs, 15 percent protein, and 10 percent fat. When following the diet, people are told to consume even six or seven meals a day. Foods are categorized into three groups: better, better still and best. You can eat as much as you want just as long as it is the proper foods. The program also calls for exercise, specifically walking 45 minutes every day.

Considered more a lifestyle than a diet, there is plenty of data to back up the claims of the Pritikin Program. For vegetarians and people suffering from heart disease, the plan is enormously popular. However, a typical person might have a hard time sticking to a diet so restrictive and so low in fat.

Using the diet in conjunction with a solid fitness plan promotes weight loss and the prevention of many diseases. The biggest flag raised about the diet is the extremely low fat intake. It is also hard to sustain if you are not ready to follow the vegetarian lifestyle. You must be ready to give up both meat and dairy, which should not be a problem if your life is at stake.