Study says Atkins side effects cloud support for weight-loss results
LONDON -- Dieters on the popular high-fat, low-carb Atkins approach lose as much body fat as those on low-fat diets, but the annoying low-carb side effects could mean problems down the road, according to a scientist who reviewed five dozen diet studies.
Dr. Arne Astrup, an authority on obesity, whose survey is published this week in The Lancet medical journal, concludes that headaches, muscle weakness, and either diarrhea or constipation are reported more often by Atkins dieters than people on conventional diets. Those side effects may be signs that the eating plan isn't healthy in the long run, he said.
Other specialists said the diet remains a viable option for some, because the side effects aren't bad enough to throw them off the eating plan famous for its shunning of bread, pasta, and many fruits.
''More people stayed in the low-carb group than in the low-fat group, so you've got to wonder how severe those side effects were if more people kept to the low-carb diet," said Dr. William S. Yancy Jr., a Duke University researcher who conducted one of the major studies that Astrup reviewed.
The Atkins diet, which allows unlimited consumption of protein and fat but drastically limits carbohydrates and does not restrict calories, has had a following for decades but only recently has come under serious scientific scrutiny. It has been embraced by an estimated 20 million people worldwide.
In his review, Astrup, director of research in the department of human nutrition at the Royal Veterinary and Agricultural University in Frederiksberg, Denmark, examined the evidence from about 60 studies on the Atkins and other low-carb diets.
Several small studies in the last year or two have surprised the specialists by showing that people lose more weight on the Atkins diet than on the standard low-calorie, low-fat diet, at least in the short term, with even better cholesterol improvements.
Longer studies have since shown that when dieters are followed for a year, the total weight loss ends up almost the same with the two approaches. The long-term effect on cholesterol has not been studied yet.
Astrup said body-composition studies indicated the weight loss is a real loss of fat, not just of water.
The most frequent complaints with low-carb diets are constipation and headache, which are readily explained by the lack of fruit, vegetables, and whole grains, Astrup said. 