Compare South Beach Diet & Atkins

The South Beach and Atkins diets are popular. They are similar in cutting carbohydrates and both are notable for quick weight loss, especially in the initial weeks. Yet they have some striking differences that dieters should keep in mind.

Similarities

Both the Atkins and the South Beach diets begin with a two-week period in which carbohydrates are severely restricted (e.g., no fruits and almost no vegetables; no bread, pasta, rice or cereals). Lean meats, fish and poultry are encouraged. In the next phases, more vegetables and other carbohydrates are allowed. These levels are increased as the dieter approaches the target weight. When the goal is reached, a maintenance phase helps to keep the pounds off.

Atkins

The Atkins Diet was first published in 1972 by Dr. Robert C. Atkins. His diet encourages eating a variety of fats, including butter and other saturated fats. Atkins dieters must count all non-fiber carbohydrates in order to stay within a 20-to-40 gram limit, depending on the phase of the diet. However, the diet is high in protein, which suppresses the appetite so those on the diet lose weight quickly.

South Beach

The South Beach diet was first published by Dr. Arthur Agatston in 2005. His diet does not allow saturated fats, such as butter, but does allow olive oil and canola oil, which are monounsaturated fats.

In terms of carbohydrates, while Atkins counts carbohydrate grams, South Beach dieters count carbohydrate portions and sizes. Carbohydrates are rated according to a glycemic index, which estimates how quickly blood-glucose levels rise after eating particular foods. Those with a high glycemic index, such as potatoes and rice, are prohibited while whole grains are not.

Do Low Carbohydrate Diets Work?

Both diets are popular because of their rapid results in the first weeks, up to 13 pounds. The South Beach Diet also claims to help people lose "belly fat," which has been linked to heart disease. Low-carb diets also help to reduce blood-cholesterol levels.

Risks

Critics of both diets have cited many health risks related to low-carbohydrate, high protein diets. According to James Kenney, Ph.D., a nutrition-research specialist board-certified in human nutrition, these risks include:
--Poor long-term weight loss
--Fainting
--Gout
--Reduced athletic performance
--Increased heart-disease and cancer risk
--Osteoporosis
--Rising blood pressure with age
--Kidney stones

Dr. Neal Barnard, a representative of the Physicians Committee for Responsible Medicine, has noted that more study is needed on the Atkins diet. He noted that while the diet is high in fat and cholesterol, these are linked to heart disease. He also noted that a meaty diet has been linked to colon cancer. The committee's website has a registry of people claiming to be harmed by high-protein diets cited low energy, poor concentration, kidney and heart related problem. While Barnard did not condemn the Atkins diet, he said more research is needed.

The Mayo Clinic noted that the first phase of the South Beach Diet, with its low carbhohydrate limit, "can result in ketoacidosis. Ketoacidosis occurs when you don't have enough sugar (glucose) for energy, so your body breaks down stored fat, causing unhealthy levels of ketones and acid to build up in your body. Left untreated, ketoacidosis can cause stupor, coma and even death."

Others have criticized both diets because of the lack of variety in the first weeks.

Which is Better?

Both diets have their merits and their drawbacks. If you feel a low-carbohydrate diet is for you, then try one of them. If you feel you need a structured diet, go with the Atkins diet. If you like the flexibility to choose from among a greater variety of foods, try South Beach.