Fad diets have been popular for years, but few have reached the notoriety of the Atkins diet which preaches low carbohydrate intake.

The cornerstone of the Atkins philosophy is a four-phase eating plan in conjunction with vitamin and mineral supplementation and exercise, according to the Atkins Web site. In the first phase of the eating program, dieters are limited to only 20 grams of carbohydrates a day.

Like with many diets, Atkins users may not be aware of all the rules and possible effects.

“People may not realize how low twenty grams really is,” said Dr. Steven Hertzler, assistant professor of human nutrition. “Common side effects are constipation and an awful nail-polish-remover-like breath.”

Nonetheless, the results are hard to refute because Atkins causes initial weight loss. According to one of the largest studies to date, Atkins dieters do lose over eight pounds more than a low-fat dieter during the first six months. After one year, however, the weight loss difference is statistically negligible, Hertzler said.

The Atkins diet is also under fire for much of the safety claims because of the studies’ short durations.

The Atkins dieters often don’t get enough fruits and vegetables, and in turn not enough of vitamins C and D – the vitamins needed for iron and calcium absorption, said Sharron Coplin, state coordinator of the expanded food and nutrition program at Ohio State.

“People don’t develop the diseases from it because they don’t stay on it long enough,” Hertzler said.

Dieters on Atkins also should be aware that many unnoticed, undiagnosed conditions may become serious on a high-fat, low-fiber diet.

“There may be some nutrients that are too high. The incredible amount of meats lead to a lot of iron,” Hertzler said. “There are about 1 in 200 people who have hemochromatosis, an iron storage problem. People with this disorder absorb way too much iron, ultimately causing liver damage or diabetes.”

The low-fiber lifestyles that are common on an Atkins diet have some health professionals concerned as well.

“A chronic low intake of fiber puts a lot of strain on the intestines to move the food down the intestinal track,”Coplin said. “This strain causes some of the muscle fibers to weaken and allow small portions of the intestine to protrude forming little pockets. This leads to a condition called diverticulosis.”

Diverticulosis can lead to hemorrhaging and may require hospitalization, according to the WebMd web site.

There may be some useful places for Atkins. Doctors at both Harvard University and Duke University have begun prescribing the Atkins diet to some patients.

“A diabetic doesn’t respond well to carbohydrates, especially a type II diabetic,” said Jeff Goshe, a medical student at Case Western. “The reason for that is because high insulin levels are bad for you, and insulin develops from carbohydrates. If you are a type II diabetic, you form a large amount of insulin. With the less carbohydrates, your blood sugar will be less likely to go out of control.”

Atkins’ treatment for diabetics also may be useful because it does cause weight loss, Hertzler said.

The lack of long term data has professionals skeptical on the diet’s safety.

“Is it is safe? We don’t know. Over a longer period of time once it has stabilized, we see that the blood values get worse. This gives us a hint that it may not be safe,” Coplin said.

As for regular dieters, there are still other ways to lose weight.

A new diet emerging is the South Beach Diet, which allows for more carbohydrates while still maintaining the “low-carb” concept. Hertzler decscribes the South Beach Diet as just another fad diet, adding it unintentionally encourages yo-yo dieting.

After all the fads have passed, it may be that the classic dieting ways will prevail as the most effective.

“In America, we’ve lost our common sense for nutrition. Good nutrition isn’t as hard as we make it,” Hertzler said.