The Grapefruit Diet (cont.)

Most versions promise a 10-pound weight loss during the 12-day diet. Dieters who want more than 12 days of monotony must wait two days before starting the diet again. Exercise is recommended in some versions and absent in others. Long-term weight control is not part of the diet plan.

The Grapefruit Diet: What You Can Eat

In most versions of the Grapefruit Diet, a small variety of foods are required at breakfast, lunch, dinner, and at bedtime. Dieters are encouraged to drink black coffee and plenty of water throughout the day.

Sample Meal Plan:

* Breakfast

2 eggs, 2 slices of bacon, black coffee, 1/2 grapefruit or 8 ounces grapefruit juice

* Lunch

Salad with salad dressing, unlimited meat, and 1/2 grapefruit or 8 ounces grapefruit juice

* Dinner

Red or green vegetables (except starchy ones such as peas, beans, corn, sweet potatoes) or salad, unlimited meat or fish, and 1/2 grapefruit or 8 ounces grapefruit juice

* Bedtime snack

8 ounces skim milk

In the Grapefruit Diet you can use all the butter and salad dressing you desire and prepare foods in any method, including fried. Grapefruit juice must be unsweetened. Any food or beverage not on the diet is not allowed. Snacking is only permitted after dinner. Drink 64 ounces of water daily. Eat all of the approved foods.

The Grapefruit Diet: How It Works

This low-carbohydrate, moderate-protein diet is another low-calorie diet averaging 800-1,000 calories in most versions. Most people will lose weight -- with or without grapefruit on the Grapefruit Diet -- when calories are dramatically reduced to this level. Unfortunately, there are no explanations for how the mysterious grapefruit enzyme works and why it is only contained in grapefruit and not other citrus fruits.

No scientific studies to date substantiate grapefruit's power to burn fat.

One small study published in 2006 and funded by the Florida Department of Citrus found that the addition of a half grapefruit or 4 ounces of juice with meals resulted in an average weight loss of more than 3 pounds in 12 weeks, with some participants losing 10 pounds. Researchers suspect the addition of grapefruit to the otherwise healthy meals reduced insulin levels and promoted a small weight loss. Study participants also "slightly enhanced" their physical activity, which could also explain the weight loss.