Dieting at work may be advantage
Low-carb regimen does well in study
Low-carbohydrate and so-called Mediterranean diets may be more effective than low-fat diets, according to a major new study published in today's New England Journal of Medicine.
Researchers studied 322 moderately obese employees of a research center in Israel, randomly assigning them to three diet groups and providing them with encouragement and instruction over a two-year period.
Members of the low-fat group lost an average of 6.4 pounds, while those in the low-carb and Mediterranean groups lost about 10, said Dr. Meir Stampfer, nutrition professor at the Harvard School of Public Health and the paper's senior author.
While there has been concern that low-carb diets can be harmful to cardiovascular health, Stampfer said that the participants who followed the low-carb and Mediterranean diets actually had better cardiovascular health than those in the low-fat group. For people with cholesterol problems, the low-carb diet seemed best; for those at risk for diabetes, the Mediterranean diet provided more health benefits.
"The take-home message should be that we should abandon the idea that low-fat diets are the number one way for people to lose weight," he said. "It wasn't the best diet. It can be helpful for some people, but overall I think the first choice should be the Mediterranean or the low carb."
Study participants generally ate lunch at the same cafeteria, where foods were color-coded with stickers to correspond to the different diets; they also met with dietitians periodically over the two years. People in the low-fat group were advised to eat low-fat grains, vegetables, fruits, and legumes and were told to avoid sweets. In the low-carb group, participants were advised to choose vegetarian sources of fat and protein and to limit carbohydrate intake. Those on the Mediterranean regimen were advised to eat a diet high in fish and poultry, as well as olive oil and nuts.
Participants, 86 percent of whom were men, were encouraged to continue the eating patterns at home. Calories were not limited in the low-carb group, but in the other groups, women were expected to eat 1,500 calories a day and men, 1,800.
One of the study's great strengths, Stampfer said, was that after one year, 95 percent of participants were still following the diet, and 85 percent stayed on after 2 years. Most people have trouble sticking with regimens for that long.
This suggests that diets connected to the workplace may be particularly effective, according to Susan Roberts, a Tufts University nutrition professor.
"Whether Americans would want this is another story of course," she said in an e-mail. "It seems fairly invasive to have overweight people in your company selected out for dietary instruction and monthly weigh-ins."
Business groups agree that workplace diets pose ethical problems. "We would never ever say we're putting our employees on a diet," said LuAnn Heinen, vice president of the nonprofit National Business Group on Health. "But companies have really connected the dots: We're paying for healthcare costs, our employees are paying for healthcare costs, and we're serving them Krispy Kremes every morning."
Instead of diets, she said, businesses are now taking steps to write caloric limits or nutritional guidelines into their contracts with food service providers.
Roberts said it's not clear from the research whether an individual, dieting without the workplace support provided by the study, would have the same success.
