The Promise

"Feel fit and boost your health -- in just weeks!" So say the authors of this low-carb diet that once topped The New York Times best-seller list in its category for more than a year.

Written by husband and wife Michael R. Eades, MD, and Mary Dan Eades, MD, the book provides scientific explanations, encouragement, and practical suggestions, such as what to order when you're eating out. The Eadeses also have a Protein Power web site and 13 other books to their credit.

The diet is basically a low-carb, high-protein eating plan with a lot of scientific explanations about insulin and glucagons, the major hormones that turn food into fuel for your body.

The idea is that by limiting carbs, you lower your insulin level. That leads your body to make more glucagon, which helps burn stored fat. Do this long enough, and the fat seems to melt away, the authors claim.

What You Can and Can't Eat

For protein, you can eat fish, poultry, red meat, low-fat cheese (cottage cheese, feta, mozzarella, Muenster), eggs, and tofu.

Also allowed: leafy green vegetables, tomatoes, peppers, broccoli, eggplant, zucchini, green beans, asparagus, celery, cucumber, and mushrooms.

The plan calls for you to get 25 grams of fiber every day. (For comparison, one cup of whole wheat spaghetti has 6 grams of fiber.) You can also have some fats: olive and nut oils, avocado, and butter.

You can have diet sodas and artificial sweeteners in moderation.

A glass of wine or a light beer is OK, but their carbs count, too.

To round out nutritional needs, the authors recommend taking a high-quality vitamin-and-mineral supplement, along with at least 90 milligrams of potassium.

Level of Effort: Medium

Like many high-protein, low-carb diets, you may really need to change what you're eating while you're on this plan.

Limitations: Low-carb diets cut out a lot of foods.

Cooking and shopping: The book has sample menus with more than 100 recipes, and suggestions on how to order in every kind of restaurant.

Packaged foods or meals: None are required.

In-person meetings: No.

Exercise: Yes. The authors suggest resistance training, such as weight lifting, to help burn stored fat.

Does It Allow for Dietary Restrictions or Preferences?

Vegetarians and vegans: This diet could work for you, but you would be eating a lot of tofu for the protein.

What Else You Should Know

Cost: No costs apart from the food you buy.

Support: The Protein Power website includes a forum, in case you want to get in touch with other people on this diet.

Does It Work?

A high-protein diet can help you lose weight. A number of studies show that diets higher in protein keep you fuller better than other types of diets. Other studies show that restricting carbs, as a result of a high-protein diet, causes more weight loss. But calories still count!

Is It Good for Certain Conditions?

The Protein Power diet could work for people with diabetes, high blood pressure, heart disease, or high cholesterol. The Power Protein diet is a low-carb diet with less than 20% of total calories from carbs or less than 100 grams of carbs per day. Limiting carbs may help lower blood sugar, insulin, bad cholesterol, and blood pressure. It also can boost HDL ("good") cholesterol.

But getting too much protein can raise your uric acid levels, which can cause gout. Too much protein load also could be a problem in anyone with kidney problems.

You also need to make sure that you're not getting too much fat from your food if your doctor has given you guidelines on that to help lower your cholesterol, for instance.

Women of childbearing age need folate, which is added to flour, and if you cut out carbs, that will mean you get less folate. Prepregnancy weight loss is best done with a more balanced approach that cuts calories.

The Final Word

It's a simple dieting approach that essentially eliminates one major food group, and, like any restrictive diet, it is difficult for most people to sustain for a long time.

This diet will help you lose weight, but if you have a specific nutritional need this may not be the diet for you. You may need to take a daily supplement to cover any nutritional gaps in vitamins and minerals.