Educação pode mudar sua vida

London (AP) People on the popular high-fat, low-carb Atkins diet lose just 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.

Danish obesity expert Dr. Arne Astrup, 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 says.

However, other experts said the diet remains a successful option for some because the side effects aren't bad enough to throw them off the eating plan famous for its avoidance 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 William Yancy, 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. It has been embraced by an estimated 20 million people worldwide but only recently has come under serious scientific investigation.

Experts have suspected that the weight loss on a low-carb diet may be largely due to water loss, because lots of fluid is bound up in the body's carbohydrate stores that are depleted. However, Astrup said body composition studies indicated the weight loss is a real fat loss, not just 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.

Also, bad breath, muscle cramps, diarrhea, general weakness and rashes are more often reported on low-carb diets than on low-fat diets, Astrup found. "The majority had some of these side effects in the Atkins group. In the control group, almost nothing," he said.

These side effects are consistent with arbohydrate deficiency, because the brain and muscle do not get enough sugar from carbohydrates to maintain their normal function, Astrup said.

But Yancy, the U.S. researcher, said side effects were seen not just after six months but also at the beginning and could have been from dehydration, which is easily overcome.

"We know that it works," Yancy said. "I think it's good that people are acknowledging that this diet might be a reasonable option. At this point, we need options and when we're looking for them we need to consider even things that go against our judgment sometimes."