Researchers plan to put low-carb lifestyle to test against low-fat diet

• A group of Portland researchers hopes to judge the long-term effect by putting 240 area residents on a diet for 21/2 years.
• The study should show which plan works better, even if the difference between the groups' average weight loss is as little as 2 pounds, said Njeri Karanja, the scientist leading the effort.
• "Basically, we just wanted to follow what the population was doing" by studying low-carb diets, said Karanja, a senior investigator at Portland's Kaiser Permanente Center for Health Research.
• "A lot of patients were coming to their doctors and saying they were following this diet, and the doctors didn't know what to tell them."
• Short-term studies have eased some early concerns that low-carb diets would be useless, or would quickly cause kidney, liver or heart problems.
• In fact, low-carb diets have beaten other plans for short-term weight loss in several studies.
• However, what long-term data exist suggest that low-carb diets are hard to stick to and may lead to less long-term weight loss than traditional low-fat diets.
• That plan, developed in large part by Karanja and Kaiser colleagues, was included as an example of healthy eating in the federal Dietary Guidelines for Americans released last week.
• Volunteers will be asked to follow their diet's principles, but they will get to make their own choices about buying and eating food.
• Health workers will check patients throughout the study, looking both at weight loss and at measures of health, such as cholesterol levels.
• She hopes that half the volunteers enrolled will be men, and that 48 volunteers, or 20 percent, will be members of ethnic or racial minorities.
• Researchers at Kaiser and Oregon Health & Science University are conducting the study, which is supported by a $3.3 million grant from the National Center for Complementary and Alternative Medicine.