Study backs low carb diets

22may03

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LOW carbohydrate diets are more effective than calorie counting in helping obese people shed weight, the latest medical research suggests.

The Atkins Diet, championed by svelte celebrities but lambasted by nutritionists, has earned praise from authors of the latest study in the New England Journal of Medicine.
It allows unlimited meat, fish, eggs and shellfish but only small amounts of bread, potatoes and pasta.

The study accepts there are question marks about the long-term impact of a low carbohydrate diet, including problems with raised cholesterol. But researchers concluded it was more effective than a calorie and fat-restricted diet after studying more than 100 severely overweight adult over six months.

Volunteers on the low carbohydrate diet were limited to 30g a day or less intake of carbohydrates but had no restrictions on the amount of fat consumed. The other half had to stick to a diet with a deficit of 500 calories a day and with 30 per cent or less of total calories derived from fat.

Almost 15 per cent of the low carbohydrate dieters achieved a weight loss of at least 10 per cent compared with only 3 per cent of those calorie and fat counting.

The Philadelphia Veterans Affairs Medical Centre team, led by Frederick Samaha, said they could not rule out that the additional weight loss was due to an overall reduction in calories among the low carbohydrate group, who were encouraged to eat vegetables and fruit with a high ratio of fibre to carbohydrate.

But they added: "Subjects in this group may have experienced greater satiety on a diet with liberal proportions of protein and fat. However, other explanations include the simplicity of the diet and improved compliance related to the novelty of the diet."

But they warned of uncertainty over the value of a low carbohydrate diet for longer than six months and called for further study of cardiovascular risk associated with the high-fat intake before the diet could be endorsed.

The study is likely to fuel the growing debate about the popularity and safety of low carbohydrate diets.

Celebrity advocates of the Atkins Diet include Geri Halliwell, Nigella Lawson, Jennifer Aniston and Brad Pitt.

A study published in the Journal of the American Medical Association last month found no evidence to support a direct link between weight loss and low carbohydrate diets -- and also warned that long-term effects were unknown.

The authors concluded that weight loss while on the diets could be attributed to a reduction of overall calories intake.

Dieticians Association of Australia spokeswoman Carole Richards said: "I would recommend a low carb diet for the short term, if that was the way someone wanted to go. But long term, a balanced approach and changes to what they are eating and doing is the only way you are going to maintain weight loss -- and that's the important thing."

While a low carbohydrate, high protein diet could prevent hunger pangs and leave people feeling full, it could place a strain on the digestive system, she said.

"A low-carbohydrate diet may also be high in fat and low in fibre -- and fibres are magic," she added.