Atkins Diet -- It's the Calories
Volumetrics author Barbara Rolls, PhD, who holds the Guthrie Chair in Nutrition at Penn State University, offers a very simple explanation as to why people lose weight doing Atkins: They're cutting calories, even if they don't realize it. "No one has shown, in any studies, that anything magical is going on with Atkins other than calorie restriction. The diet is very prescriptive, very restrictive, and limits half of the foods we normally eat," she says. "In the end it's not fat, it's not protein, it's not carbs -- it's calories. You can lose weight on anything that helps you to eat less, but that doesn't mean it's good for you."
To be fair, the Atkins diet has gotten a somewhat undeserved reputation as an "all cheeseburgers, no vegetables" plan. Although the early "induction" phase drastically reduces carbohydrate consumption, requiring no fruits and only a very few leafy greens, that's only the first two weeks. "Induction is very severe, but then you go up the carbohydrate ladder. You may end up eating a fair amount of carbohydrates again six months down the line, although the diet really advises you to avoid some things, like white breads, white potatoes, and white rice, forever," says Foster. "People will say that Atkins doesn't let you eat fruits and vegetables, and that's inaccurate. He advises you to add fruits and vegetables and whole grains early on in the process."
But the diet still isn't balanced, says the American Heart Association, troubled by implications that it's changed its position on Atkins since the November meeting. (It hasn't.) "A high intake of saturated fats over time raises great concern about increased cardiovascular risk; the study did not follow participants long enough to evaluate this," the AHA said in a release.
So why did "bad cholesterol" levels go down for Atkins dieters in the studies? "Any time people lose weight by any means, cholesterol goes down," says Neal Barnard, MD, president of the Physicians Committee for Responsible Medicine and a leading Atkins critic. "But the idea that Atkins is a cholesterol-lowering diet -- the evidence on that is at best very mixed."