Atkins diet has long-term dangers, researchers warn

The pounds may fall off in the first few months but the Atkins diet does not help people lose weight in the long term and it may be dangerous, according to a scientific review of research.

The pounds may fall off in the first few months but the Atkins diet does not help people lose weight in the long term and it may be dangerous, according to a scientific review of research.

More than 45 million copies of the Atkins diet books have been sold which recommend unlimited consumption of butter, fatty meat and high-fat dairy products while carbohydrate intake is restricted to under 30g (1oz) a day, equivalent to a small potato.

People who follow the diet do lose weight more quickly than on standard diets, but the weight loss is not sustained. Studies of the diet in obese men and women showed that they lost up to 4.6kg (10.1lb) more over six months than those who followed conventional low-calorie, low-fat diets. But by 12 months there was no significant difference between the two groups.

Danish researchers who conducted the review, published in The Lancet, say the diet may be safe to use in the short term - up to six months - but that side-effects were more worrying in the long term.

Arne Astrup, of the Centre of Advanced Food Research in Copenhagen, who led the study, said: "Our conclusion is a little more liberal than the conventional medical view that the Atkins diet is bad for you. In the short term the diet is producing a weight loss and it is not just fluid loss - there is a loss of fat. At the same time it is producing a beneficial effect on the blood in terms of blood pressure, blood sugar and cholesterol levels.

"All the complications of being overweight look better on the Atkins diet and we have no real reason to say that it should not be used in the short term for a couple of months."

The likely reason for its success in promoting weight loss was that the diet restricted food choices, in common with many other diets, and that protein was better at satisfying hunger than fat.

Professor Astrup stressed that there was little scientifically robust evidence on the effects of the diet and new research could reveal hidden risks. Few studies have looked at long-term risks. Those that had been conducted showed people tended to regain their lost weight after one year and were more likely to complain of side-effects.

Professor Astrup said: "They start to suffer headaches, muscle cramps and diarrhoea. This is consistent with a carbohydrate deficiency. They simply do not get enough carbohydrate to supply the tissues with blood sugar. That is why the organs start to malfunction." The minimum daily requirement of carbohydrate for an adult is 150g a day. On the Atkins diet, carbohydrate intake is restricted to one fifth of that level.

The researchers conclude that the lack of long-term studies means the diet cannot be recommended. They say restricting the intake of whole grain bread and cereals, fruit and vegetables does not equal a healthy diet and the absence of these food groups may increase the risk of heart disease and cancer. "There is no clear evidence that Atkins-style diets are better than any others for helping people stay slim. Although the diet appears to promote weight loss without hunger, at least in the short term, the long-term effects on health and disease prevention are unknown."