Still No Perfect Diet
A new study pits protein against carbs against fat
Christopher Gardner, a nutrition scientist at the Stanford Prevention Research Center and lead author of the study, thinks the Atkins diet may have had an edge because it's so straightforward. "Their very simple message hits it right on the head: Drastically reduce your carbs," he says. Protein may also be more filling, and the diet's emphasis on drinking lots of water may crowd out calories from an extra gulp of an energy drink here or a half a soda there.
Regain. Of course, what works in the short term may not be a solution for the long haul. While the Atkins group lost more weight in the first six months, those participants gained some of the pounds back in the next six months. Ditto with the other diets. And Gardner emphasizes that the Atkins diet may not be a healthful choice over many years if devotees go heavy on the saturated fat. Sure, women on it got good marks on HDL cholesterol and triglycerides tests, but whether that was because of the proportion of carbs and protein or the weight loss is impossible to tell. Over time, says Gardner, high amounts of protein may knock the body out of balance, stressing the kidneys and potentially weakening bones. Jacqueline Eberstein, a nurse who worked with Atkins for 30 years and is now a nutrition consultant, says those fears are speculative and based on studies that don't apply specifically to Atkins.
These were real women in the real world, not rats in a lab, so it's no wonder that researchers also found that the participants didn't follow the diets to the letter. By the end of the study, the Atkins group was getting almost 35 percent of calories from carbs, instead of 10 percent, while the Ornish gaggle far exceeded the diet's recommendation of no more than 10 percent of calories from fat. Still, while the average weight loss was low, at least some women in every group lost significant weight.
That lack of adherence led Sears and Ornish to complain that the study wasn't a fair test. "What happens when you follow the diet is the question," says Ornish, who notes that his low-fat routine reduces heart disease. "This is the only time that Dean and I have been together on something," says Sears.
But that disconnect is exactly the point, says Marion Nestle, a nutrition professor at New York University. Anyone can dream up a diet that will shave off pounds. It's much harder to follow that diet over many years and maintain a lower weight. "What's sustainable is eating less and more healthfully and being more active," she says. That advice is the closest to a magic pill for weight loss. Unfortunately, it's one that Americans so far have been unwilling to swallow.