NEW YORK TIMES:
More Evidence That Diets Don’t Work
As if we needed a reminder that diets mostly fail, The New England Journal of Medicine has published a new report on an intense, tightly controlled experiment involving more than 300 moderately obese people.
After two years of effort the dieters lost, on average, 6 to 10 pounds. The study, funded in part by the Atkins Research Foundation, seemed designed to prove that low-carb diets trump low-fat diets. But in the end, all it really showed is that dieters can put forth tremendous effort and reap very little benefit.
Dr. Dean Ornish, a proponent of low-fat diets, is critical of the study design, particularly the fact that the so-called “low-fat” diet group was really only a moderate-fat diet that included about 30 percent of calories from fat.
The New England Journal report also affirmed something many women have believed all along — that low-carb diets work better for men than women. Male low-carb dieters lost about 11 pounds, compared to about 9 pounds on a Mediterranean diet. Women low-carb dieters lost only about 5 pounds, compared to about 14 on the Mediterranean diet. To read more about the new research, read below:
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NEW YORK TIMES:
Healthy Diets Shown to Have Benefit Despite Modest Weight Losses
By: Tara Parker-Pope
In a tightly controlled dieting experiment, obese people lost an average of just 6 to 10 pounds over two years.
The study, published Thursday in The New England Journal of Medicine, was supposed to determine which of three types of diets works best. Instead, the results highlight the difficulty of weight loss and the fact that most diets do not work well.
The researchers followed 322 dieters, 277 men and 45 women. The dieters were assigned to follow one of three types of diets — a diet with about 30 percent fat, based on American Heart Association guidelines; a Mediterranean diet; and a low-carbohydrate diet based on the Atkins diet plan. The study was partly financed by the Atkins Research Foundation.
The trial was conducted at the
In addition to regular meetings and telephone calls with dietitians for the participants, the plan included nutrition counseling for spouses and a revamping of the food served in the center’s cafeteria.
Because the center is in an isolated area, the dieters consistently ate lunch, the largest meal of the day, in the company cafeteria, where food was color-coded to help dieters comply with their eating plan.
The biggest weight loss happened in the first five months of the diet — low-fat and Mediterranean dieters lost about 10 pounds, and low-carbohydrate dieters lost 14 pounds.
By the end of two years, all the dieters had regained some, but not all, of the lost weight. The low-fat dieters showed a net loss of six pounds, and the
Researchers said the results sound modest, but they said the small weight loss had resulted in improvements in cholesterol and other health markers.
“In order to keep participants on the diet for long term as a way of life, we did not impose extreme diet protocols,” said Iris Shai, the study’s lead author and a registered dietitian at
There were subtle differences in the three diets studied. Men did better on the low-carbohydrate diets, losing 11 pounds compared with about 9 pounds for the Mediterranean diet.
Women fared best on the Mediterranean diet, losing about 14 pounds compared with about 5 pounds on the low-carbohydrate plan.
For all dieters, there were improvements in the ratios of good to bad cholesterol.
“This suggests that healthy diet has beneficial effects beyond weight loss,” Ms. Shai said.