Criticism of the Diet

In several years while the diet was very popular, it has also experienced some serious critics from several different sources. Low-carbohydrate diets have been the subject of heated debate in medical circles for three decades:

Forbes magazine

Forbes magazine found that the Atkins Nutritional Approach is one of the five most expensive diet plans of the ten plans Forbes analyzed. The Atkins diet nevertheless involved more than an 80% premium over average American food expenses.

National Weight Control Registry

This company was tracking the habits of successful dieters over a period of 10 years. Despite this diet's overwhelming popularity compared to other diets, of the 5,000 Americans confirmed to have lost an average of 32 kg  who were able to prove they have kept it off for at least 6 years of the decade, less than 1% were confirmed to be Atkins adherents.

Obesity Research magazine

A 2001 scientific review by Obesity Research magazine has determined that initial advantage in weight loss was a result of increased water loss, and that after the initial period, low-carb diets produce similar fat loss to other diets with similar caloric intake.
 
Physicians Committee for Responsible Medicine

This organization has noted that in East Asian countries, the average person's diet consists mainly of carbohydrates but these countries have very low rates of obesity. 

Studies on Atkins diet

Two studies supporting the diet and confirming the weight-loss ability have been publicized. The question is were they reliable enough?

The first study
The first was conducted by the Philadelphia Veterans Affairs Medical Center, where 132 severely obese patients were randomly put on either a low-carbohydrate diet or the low-fat diet. Only 79 people managed to complete the six-month trial. Low-carbohydrate dieters lost an average of 13 pounds, compared to four pounds for low-fat dieters.

The second study
The second study was carried out over one year, led by researchers at the University Of Pennsylvania School Of Medicine. Only 63 obese men and women took part, and were either assigned to a low-fat diet or the Atkins approach. They discovered that at three months, Atkins dieters had lost an average of 14.7 pounds, compared with 5.8 pounds average the low’fat dieters lost; at six months the losses were 15.2 pounds and 6.9 pounds respectively.

There are several reasons why we shouldn’t rely on these studies:

• Both studies were very small.
• Both used obese, or severely obese, participants, which isn't representative of the average dieter.
• There was a high drop-out rate, suggesting that people found the Atkins diet hard to stick to.
• They didn't address the harmful effect the diet could have on the kidneys.
• The difference between the weight losses at the end of the studies wasn't really that big