How best to lose weight and keep it off is a national obsession. Of the many weight-loss programs available, the Atkins diet is the most controversial. On the surface, this approach to dieting seems like nothing short of lunacy. Everything we have learned over the past 50 years is thrown out the window.

Dr. Robert Atkins believed that the best and healthiest way to lose weight is to become a true carnivore. Eat steak, bacon and as much fat as you want, but at all costs, avoid carbohydrates. No rolls, pasta, rice or potatoes. Even fruit is strictly limited. And the diet does work. Pounds melt off and surprisingly, despite the high fat, total and bad or LDL cholesterol falls, metabolism improves and risk of diabetes decreases — truly incredible and to the skeptics (that includes me), too good to be true.

Those who oppose the Atkins diet raise serious questions about the long-term effects of a high-fat diet that may increase the risk of breast, colon and prostate cancers, heart attacks, strokes and even Alzheimer's disease. The proponents of the diet argue that limiting carbohydrates significantly reduces total calorie intake, improves the ability of insulin to function and lowers blood pressure; they suggest that the Atkins diet may, over time, prevent rather than cause heart disease.

The antithesis of the Atkins diet is one developed by Dr. Dean Ornish, whose vegetarian diet is rich in fruits, vegetables and complex carbohydrates. Fat intake is kept at a minimum. In combination with lifestyle changes, rigorous study indicates that this weight-loss program promotes a longer life and decreases risk of heart attacks in healthy people and in those with severe coronary artery disease.

Somewhere between Ornish and Atkins is the Zone diet, based on the principle that excess insulin, a hormone that controls blood sugar, leads to increased appetite and preferential formation of fat at the expense of muscle. To assure that insulin levels are in the ideal "zone," every meal must be balanced and the proportion of total calories as carbohydrates, fat and protein are strictly controlled. Staying on the Zone diet and preparing your own meals is virtually impossible. Realistically, the only way to participate in the Zone is to purchase prepared meals — a billion-dollar industry. Although less well studied, there is general consensus that this diet is as good as any other.

So which diet is best? To answer this question, the National Institutes of Health funded a study that, in an unbiased way, compared the effectiveness of the Atkins, Ornish and Zone approaches to weight loss in more than 300 overweight premenopausal women. They also compared these diets to one felt to be ideal by most clinical nutritionists. This weight-loss program is called LEARN (Lifestyle, Exercise, Attitudes, Relationships and Nutrition) and consists of a diet low in fat, high in carbohydrates and based on national guidelines for nutrient intake. A key component is intensive counseling to assure adequate exercise and stress reduction. It's a total makeover that emphasizes lifestyle changes as much as it does dieting.

The results of this study, just published in the prestigious Journal of the American Medical Association, are unambiguous. Weight loss occurred most rapidly in the women on the Atkins diet. After one year those on the Atkins diet had lost the most weight, on the average five pounds more than the other diets. Blood pressure was lower, as was the cholesterol level.

So what can we conclude from this study? If you want to lose weight rapidly, the Atkins diet is for you and at one year you will likely be thinner than if you were on one of the other diets. However, the study tells us nothing about the long-term effects of a high-fat, low-carbohydrate diet. We do know that it is virtually impossible to stay on this diet indefinitely. Eventually you will be eating too much fat and too much carbohydrate — a prescription for disaster.

Quick fixes over one month or one year are never the solution. The best diet is still the don't-diet diet. Only through total lifestyle changes will a healthier and happier life be guaranteed. Diets don't work; they never have and never will.

Dr. David Lipschitz is the author of the book "Breaking the Rules of Aging." To find out more about Dr. David Lipschitz, and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate Web page at www.creators.com. More information is available at www.drdavidhealth.com.