DON'T TRY THIS AT HOME!

If you hove diabetes, don't try the Atkins diet on your own.

Cutting your carbohydrate intake to almost nothing without adjusting your diabetes medications could raise your insulin level dangerously high and knock your blood glucose (sugar) dangerously low, throwing you into a hypoglycemic crisis. Even the creator of the Atkins diet, Robert Atkins, MD, warned: "If you are currently taking diuretics, insulin, or oral diabetes medications, you must undertake Atkins only under the guidance of a physician."

A funny thing happened to the scientifically unfashionable, high-protein/low-carbohydrate Atkins diet when skeptical scientists finally gave it a serious tryout: It seemed to work.

According to a flurry of studies in top-of-the-line medical journals last year, the Atkins diet, which amounts to, "Eat all the meat you want but cut down drastically on bread, potatoes, and other carbs," seemed to work at least as well as other weight-loss programs. There were signs it might even work better, and it didn't seem to do any serious harm to the people who followed it.

"Now we have data," says Samuel Klein, MD, of the Washington University School of Medicine in St. Louis, Mo., a coauthor of one of the key studies. "People on an Atkins-type diet lose more weight than people on a traditional diet over the first six months. After that, it's unclear."

The outcome of the new studies startled the medical-nutritionist establishment, surprised even some of the scientists who conducted the studies, and turned conventional nutritional wisdom upside down.

Traditionally, doctors have advised overweight patients to lower their caloric intake and cut down on fats. Expert groups such as the American Heart Association and the American Dietetic Association have warned against experimenting with the Atkins diet.

In fact, the model of a well-rounded, healthy diet, proposed in September 2002 by an expert committee of the Institute of Medicine, draws 45 to 65 percent of its calories from carbohydrates, 20 to 35 percent from fat, and only 10 to 35 percent from protein. Moreover, the base of the U.S. Department of Agriculture's Food Guide Pyramid is carbohydrate--six to 11 servings a day from the bread, cereal, rice, and pasta group.

lf the new research is correct, then for decades, the conventional medical advice has been wrong--or at least, incomplete--and promoters of the high-protein Atkins diet have been right.

Caveats Abound

However, it's too early to declare victory for either side. The new studies are relatively short term. Only two lasted as long as a year. They involved only small groups of people. And their outcomes are ambiguous: People on low-carb, Atkins-style diets tended to lose more weight over the first three to six months. But in the two trials that extended to 12 months, there was little difference between Atkins and conventional dieters by the end of the studies. A third or more of the dieters dropped out. And the trials did not test fully for possible high-protein side effects such as kidney damage. (See "Gaining Respectability?" below.)

One fact is clear, though. If you have diabetes, you shouldn't try Atkins or other low-carb diets unless you are under the direction of your doctor. Drastically cutting your intake of carbohydrates without adjusting your insulin or other diabetes medicines will quickly raise your insulin levels and bring on low blood glucose (hypoglycemia) that could cause coma or death.

Even the founder of the Atkins diet, the late Robert Atkins, MD--who wasn't shy about trumpeting the virtues of his approach--warned in the 2002 edition of his book Dr. Atkins' New Diet Revolution, "If you are currently taking diuretics, insulin, or oral diabetes medications, you must undertake Atkins only under the guidance of a physician."

"That's the one thing I would agree with," says Frederick Samaha, MD, of the Philadelphia Veterans Affairs Medical Center, who headed one of last year's six-month trials. Nearly 40 percent of the 79 severely obese people in Samaha's trial had diabetes, but they all remained under the care of their primary doctors, who stayed in touch with the clinical trial physicians.

In Samaha's trial, the mean fasting glucose (sugar) levels of people with diabetes declined more in the low-carb group than the conventional-diet group--that is, their condition improved. But the improvement in insulin levels seemed to have more to do with weight loss than with the particular diet.

More Information Needed

For now, Samaha says, too many questions remain unanswered. "I personally am not advocating this diet yet for people with diabetes," Samaha adds.

Nor are other researchers urging Atkins on patients now. "It's not responsible to change the public health message based on three very small, very short-term studies," says Gary Foster, PhD, of the University of Pennsylvania School of Medicine in Philadelphia, coauthor of a year-long study that found the Atkins and conventional diets roughly equal.

Among the unanswered questions, perhaps the biggest is: How does the Atkins diet work--if it does work?

Atkins, who died last year at the age of 72, contended that his approach shocks the metabolism into a new gear, in which the body generates energy by burning its stored fat rather than burning glucose derived from carbohydrates.

Once this "metabolic advantage" is turned on, Atkins promised in his books, a dieter can stop worrying about calories. Excess calories add pounds "only when you are eating a lot of carbohydrate along with fat," he wrote. In fact, "this metabolic correction is so striking that some of you will be able to lose weight eating a higher number of calories than you've been eating on diets top heavy in carbohydrates."

Most conventional nutrition experts don't buy that explanation. The Atkins diet "works because you eat less food--although you're more satisfied, because protein is more satisfying, and so is fat," says Madelyn Fernstrom, PhD, CNS, director of the weight management center at the University of Pittsburgh.

Atkins In A Nutshell

Whether real or imaginary, the metabolic advantage is at the heart of the Atkins approach.

Atkins divided his diet into four stages: Induction, Ongoing Weight Loss, Pre-maintenance, and finally, Lifetime Maintenance.

The Induction phase is aimed at knocking dieters' metabolism from glucose-burning to fat-burning, and it's the toughest. For two weeks, dieters are told to limit their carbohydrates to 20 grams a day. And that's vegetable carbohydrate--no bread, no pasta, no potatoes, no rice, no grains, no fruit, no starchy vegetables, no nuts. And no sugar.

How much is 20 grams of carbs? A cup of brussels sprouts, or maybe spinach, and two cups of salad vegetables will do it. Bon appetit.

Atkins dieters can nibble a little cheese, but not much. An ounce of cheddar or Swiss cheese equals a gram of carbs. No cottage cheese; that's too high in carbs.

On the other hand, even in the Induction phase, Atkins dieters can eat all the fish, fowl, and meat they want, although they should go light on cuts like bacon, ham, and organ meat.

This ultra-low-carb regimen, according to Atkins, denies the overweight body the carbohydrate fuel that it has gotten accustomed to transforming into glucose and burning for energy. This, in turn, ratchets down the unhealthily high level of insulin that Atkins claimed was responsible for transforming excess carbs into body fat. And at this point, Atkins' "metabolic advantage" kicks in, and the body begins to burn its accumulated fat.

Atkins, who was nothing if not a breezy salesman, promised in his book that the Induction phase will "knock your socks off by demonstrating how much body fat you can burn, while eating liberally, even luxuriously, off the fat of the land."

During the next phase, Ongoing Weight Loss, Atkins dieters transition to an easier, longer-term carb level. Each week, they raise their daily carb intake by 5 grams--increasing the variety of permitted foods--until they are losing about 2 pounds a week. Then they stick with that for months, until they are 5 to 10 pounds away from their target weight.

Now comes the Pre-Maintenance phase. Each week, dieters raise their daily carb level by 10 grams. Their weight loss slows. Finally, they stabilize at their target weight--and continue to count carbs for the rest of their lives. In the fourth, so-called Lifetime Maintenance phase, dieters' daily carb intake may be as low as 25 grams or more than 100 grams; everybody's is different.