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. He writes more about the issue in a Newsweek column here.

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, click here.