The researchers assigned patients to either a low-carbohydrate or a low-fat diet. They instructed the low-carbohydrate group to eat no more than 20 grams of carbohydrate per day for 3 months and then increase by 5 grams per day each week until they achieved their desired weight. The low-fat diet group received instructions to decrease calorie intake to 1200 to 1800 kcal per day with no more than 30% of calories from fat. All patients also participated in an education program on changing physical activity and other lifestyle factors. This program met weekly for 20 weeks, then every other week for 20 weeks, and then monthly for the rest of the 2-year study. The researchers collected information about weight at the start of the diet and after 3, 6, 12, and 24 months. They also collected information on cholesterol levels, blood pressure, bone density, and side effects.