With ephedrine-based weight-loss products disappearing from store shelves as quickly as fat through a liposuction tube, more customers are turning to dieting the traditional way: by the book.

From Atkins to the Zone, diet books are perennial best sellers. In late February, six of the top 10 sellers in the Health, Mind & Body category on Amazon.com were diet books; five of the top 25 best sellers overall were about weight loss. Diet books are also good business for natural foods retailers. Not only do dieters frequently need to stock up on everything from peaches to pork to be faithful to the regimen presented in their diet book of preference, but most of those books also encourage them to take vitamins or supplements.

The bottom line is that just because a dieter may be eating less food doesn't mean he or she is spending less money on groceries. Quite a few recipes in weight-loss books call for specialty produce or spices to make fat-free food taste good. Savvy retailers recognize the opportunities offered by various popular diets. Here's a look at eight of the top-selling diet books and a survey of their pros and cons, plus suggestions for merchandising tie-ins.

To evaluate the diets, we assembled a team: Douglas Kalman, a registered dietitian in Miami and director of nutrition & applied research at Miami Research Associates; Tammy Baker, a registered dietician in Phoenix and spokeswoman for the American Dietetic Association; and the nutrition staff of the Physicians Committee for Responsible Medicine in Washington, D.C.

Body for Life: 12 Weeks to Mental and Physical Strength by Bill Phillips and Michael D'Orso (HarperCollins, 1999)
This program, developed by EAS Inc. founder Bill Phillips, calls for a 12-week commitment. Participants eat six high-protein meals a day, with a "cheat day" once a week. Dieters also do an hour of aerobic exercise and 2 hours and 15 minutes of weightlifting each week.

Kalman: The basic premise is a great one—get people motivated to exercise and eat better, thus gaining better control of their bodies' appearance, health and look. While the intricacies of the book may be hokey and scientifically off base, the message is a good one.

Baker: The exercise is really important in helping boost metabolism, but it might be something people have to ease into.

PCRM: Two stars: unsatisfactory. Body for Life's meal plan is low in fat and saturated fat, but its reliance on supposedly "lean" meats packs in an unhealthy dose of cholesterol and squeezes out healthy high-fiber foods such as fruits and vegetables. Dieters would do better to stick with diets that rely on plant protein sources, which are far leaner.

Merchandising opportunities: Phillips refers to EAS supplements and frequently mentions EAS's Myoplex shakes. If you don't carry EAS, other supplements tie-ins can lure Body for Lifers, as can a display in the meat department.

Dieting With the Duchess: Secrets and Sensible Advice for a Great Body by Sarah Ferguson (Fireside, 2000)
Part autobiography and part weight-loss pep talk, this book by the Weight Watchers spokeswoman also delivers a primer on food fundamentals and recipes that follow the Weight Watchers' points system.

Kalman: Weight Watchers is a good plan for those looking to lose weight. It allows you to eat the foods that you like, but assigns an easy-to-use point system as a method of calorie control. Weight Watchers allows you to add points for exercise and save points for a once-a-week mini splurge. With the group and Internet support systems, it is a good program. The downside is that there is no real education about macronutrients or the importance of vitamins and other nutrition topics.

Baker: This is a great diet—nutritionally sound, real food and not packaged meals. It has no cons.

PCRM: Didn't evaluate.

Merchandising opportunities: Weight Watchers is big business, from frozen meals to magazines.

Dr. Atkins' New Diet Revolution by Robert Atkins, M.D. (Avon, 2001)
This diet, created by a cardiologist and popularized in the 1970s, has made a resurgence in recent years. Dieters kick off their weight loss by limiting carbohydrate consumption to 20 or fewer grams a day for at least two weeks. They gradually add carbohydrates until weight loss stops, then subtract 5 g of carbohydrates daily for lifetime maintenance of their new shape. The diet is modeled on the theory that if the body doesn't have carbohydrates to burn for fuel, it will consume fat. A high-protein, low-carbohydrate diet also staves off hunger, Atkins says.

Kalman: The pro of this diet is that it works; the negative or con is that it can be hard to follow all of the time.

Baker: The plus to this diet is immediate weight loss—that's what's so appealing. Anytime you limit food groups you lose weight. Plus, with the limited food groups, people eat less out of boredom. But much of that weight loss is water. When you break down protein and fat it produces the toxic by-product of ketones that the body tries to wash out. It's not a healthy diet for a lifetime, but a couple weeks wouldn't hurt—it might jump start you into losing weight.

PCRM: No stars, unsafe. At 1,257 mg of cholesterol, 53 percent of calories from fat and 20 percent of calories from saturated fat, Atkins' diet plan wins the dubious distinction of reaching the highest amounts (of diets surveyed) in those categories. And that's for his Lifetime Maintenance Menu, the one suggested for permanent use. An analysis of Atkins' Induction Menu shows even unhealthier results. Starting the day off with meals like a Ricotta Cheese Omelette, moving into Crab Salad for lunch and concluding with Herbed-Roast Chicken means lots of fat and artery-clogging cholesterol with very little fiber, fruits or vegetables. High-protein, low-carb programs are linked to massive calcium losses and are not recommended for anyone.

(Note: PCRM is so concerned about the harmful aspects of the Atkins' diet that it's launched www.atkinsdietalert.org, where it claims that a high-protein, high-fat diet can result in colorectal cancer, cardiovascular disease, impaired renal function and osteoporosis).

Merchandising opportunities: There are more than a dozen foods and supplements produced under the Atkins label, from a bake mix to essential oils. Atkins bread is a top seller for some natural foods stores. In addition, Atkins recommends dieters take a daily multivitamin, flaxseed, borage oil, and omega-3 and -6 fatty acids. According to PCRM, the Atkins diet is low in iron, calcium, vitamin C, vitamin A, folate and thiamine—all of which can be marketed to Atkins disciples.

Eat More, Weigh Less: Dr. Dean Ornish's Life Choice Program for Losing Weight Safely While Eating Abundantly by Dean Ornish and Shirley Elizabeth Brown (Quill, 2000)
Ornish, a cardiologist, says a vegetarian diet with 10 percent of total daily calories from fat will reverse heart disease and help people lose weight. He allows egg whites and nonfat dairy or soy, with small amounts of sugar or white flour. The book also contains 250 recipes along with advice for social support and reconnecting with yourself while dieting.

Kalman: One thing he neglects to mention is that his program has many dropouts and is hard to follow. However, Dr. Ornish does have the clinical research studies to back up his lifestyle approach. Bland taste and a limited protein menu make this diet not always feasible.

Baker: The concept is good, because we need a diet high in fiber. A caution: It's important to understand how to get enough protein, calcium and adequate amounts of B-12 with this diet.

PCRM: Five stars, outstanding. Dr. Dean Ornish's approach is backed by rigorous research published in peer-reviewed journals. Dr. Ornish's menus provide the most fiber of any surveyed. This book provides flavorful and slimming recipes such as Spaghetti with Sicilian Greens, Wild Rice Pilaf with Dried Fruit and Strawberry Sorbet.

Merchandising opportunities: Ornish recommends a multivitamin and 3 g of fish oil capsules daily, with an option of 1 g to 3 g of vitamin C, 100 units to 400 units of vitamin E, 100 mg to 200 mg of selenium and 400 g to 1,000 g of folic acid daily. This is a good diet to promote near the produce displays and in the aseptic soymilk aisle.

Eat Right 4 Your Type: the Individualized Diet Solution to Staying Healthy, Living Longer & Achieving Your Ideal Weight by Peter J. D'Adamo and Catherine Whitney (Putnam Publishing Group, 1996)
D'Adamo, a naturopath, believes some foods have proteins that are close in chemical structure to antibodies that are incompatible to a particular blood type. The body mistakes this food for invaders, which can cause disease and health problems. The series includes an overview and individual books for each blood type. D'Adamo says 70 percent adherence to the diet is enough to be healthy.

Kalman: There is not one shred of scientific evidence available to support the contention that the author promotes. He believes that different blood types genetically need to eat differently. I believe he made a lot of money from the sale of this book.

Baker: This is the rage in certain circles now, but there's no research showing this works. Anytime you start limiting foods, you will lose weight, and anytime you have a diet where those foods are defined, it makes it easier.

PCRM: Type A: Three stars, marginal. Scientific research has not established that a person's blood type determines what he should eat. Dieters wishing to try one of the meal plans in this book should follow the type A diet plan, which is high in fiber, fruits and vegetables and low in saturated fat. It is still too high in fat and cholesterol to qualify as a five-star plan.

Type O: Two stars, unsatisfactory. Dieters will get moderate amounts of fiber, fruits and vegetables on the type O plan, but they will also get lots of cholesterol, fat and saturated fat. We advise people to use their blood type when donating blood and use common sense when it comes to choosing a healthy diet.

Type B: One star, poor. D'Adamo presents a frankly terrible guide for people with type B blood. Entrees like Fettuccine Alfredo and Lamb and Asparagus Stew are not recipes to be recommended to anyone who cares about health.

Type AB: One star, poor. This diet offers a mixture of the healthier type A recipes, like Maple-Walnut Granola, with unhealthy type B recipes like Grilled Rabbit.

Merchandising opportunities: Well, there's the obvious: blood-testing kits. D'Adamo recommends additional vitamins B and C, along with calcium. He says the diets can improve health to the point where they make herbal remedies superfluous.

Get With the Program! Getting Real About Your Weight, Health and Emotional Well-Being by Bob Greene (Simon & Schuster, 2002)
This weight-loss plan, developed by Oprah Winfrey's personal trainer, is more self-help manual than diet book. It divides weight loss into four phases: changing your thinking; introducing aerobic exercise; controlling emotional eating; and building muscle. It recommends dieters eat breakfast, establish an eating cut-off time at night and spread calories throughout the day. It contains a food diary and 80 recipes.

Kalman: Good premise; no overt blunders or negatives.

Baker: Metabolism is highest in the morning and lowest in the evening, so cutting off eating can be a smart thing to do. Small, frequent meals are better for you—if you dump a lot of food into your system it has to work very hard to digest it. Studies show you can do that when you're younger, but the metabolism starts slowing down in your mid-20s. The discussion about emotional eating is good because emotions can be intertwined with eating, and part of weight control is behavior modification.

PCRM: Four stars, good. Greene's book focuses more on exercise than eating. The strength of his eating approach is his emphasis on fruits, vegetables and whole grains. He also recommends limiting fat—especially saturated fat—intake. The reliance on some high-cholesterol meat dishes was the only downfall.

Merchandising opportunities: Greene is a fan of beta-carotene and antioxidants and mentions them frequently in his book.

The Paleo Diet: Lose Weight and Get Healthy by Eating the Food You Were Designed to Eat by Loren Cordain, Ph.D. (John Wiley & Sons, 2002)
The author, a Colorado State University health and exercise science professor, believes we can prevent disease and lose weight if we eat as our hunter-gatherer ancestors did: no dairy, no grains or cereals, few legumes or potatoes, no sugar, no alcohol, no oils. He recommends dieters consume 30 percent to 35 percent of their calories in carbohydrates, 35 percent to 40 percent in fat, and 25 percent to 30 percent in protein.

Kalman: This diet may have a grain of truth to its premise, that our ancestors who roamed the earth hundreds of years ago did not have the luxury of a Twinkie or even Häagen-Dazs; however, Mother Nature provided fruit, vegetables, fish and meat. Thus our diets should be what is natural from the ground up, if you will. This diet and philosophy might work for weight loss, but if you are a person who eats healthy (high fiber, low glycemic carbohydrates, moderate protein and fat), then there is no reason for this kind of diet. The Paleo diet is also not for an endurance athlete, because your glycogen stores will be greatly diminished.

Baker: We're not cavemen. We don't exercise like they did, with a lot of weight-bearing exercise. They also had a heavier body build than we do. We don't know how much our bodies have changed over the ages—routines, workstyles, lifestyles have changed. They didn't live long enough to worry about cholesterol and the need for fiber to help the gastrointestinal tract. They also probably gnawed bones for calcium and got omega-3 fatty acids from wild game.

PCRM: Didn't evaluate.

Merchandising opportunities: This is a natural food merchandiser's dream diet. Cavemen ate organically grown produce, dried fruits, flowers and nuts. Their beef was grass-fed, their game wild, and their fish caught in rivers or seas. Free-range chicken and hogs are considered Paleolithic, as are bison and the more uncommon meats such as kangaroo. Some also consider coconut and palm oils Paleolithic.

The Zone: A Dietary Road Map to Lose Weight Permanently, Reset Your Genetic Code, Prevent Disease, Achieve Maximum Physical Performance, Enhance Mental Productivity by Barry Sears, Ph.D. and Bill Lawren (HarperCollins, 1995)
Sears, a Massachusetts Institute of Technology researcher, bases The Zone on meals consisting of 40 percent carbohydrates, 30 percent protein and 30 percent fat. The diet calls for three meals and two snacks a day, with no more than five hours between meals. It emphasizes "good," or complex carbohydrates.

Kalman: This book espouses the positive effects of controlling insulin levels. Barry Sears believes that his dietary ratio will control how much glucagon and insulin are secreted in relation to the glucose load and stress throughout the day. Studies do demonstrate that a low-glycemic diet of this type of ratio does help control blood sugar and insulin to a better degree than the diet promoted for all Americans by the U.S. Department of Agriculture. For athletes who participate in true endurance events, this diet may negatively impact glycogen stores. The downside to this program is that it is extremely difficult to follow.

Baker: There may be certain populations that insulin problems can occur in, but it's not across the board. Really, diabetics or anyone prone to diabetes are the only persons for whom insulin response is important.

PCRM: Three stars, marginal. The Zone, surprisingly, offers the most servings of fruits and vegetables of any of the analyzed diet plans, with at least eight servings a day. This diet is also high in fiber and low in saturated fat. However, recipes loaded with fat and cholesterol, such as Huevos Rancheros, BLT Sandwiches and Pork Medallions and Apples, brought down its rating.

Merchandising opportunities: Like Weight Watchers and Atkins, The Zone markets a variety of products, from nutrition bars to antioxidant supplements. A search of the company's product Web site, www.zoneperfect.com, shows that few natural foods stores carry Zone-branded items.

Vicky Uhland is a Denver-based freelance writer.