PHILADELPHIA—Individuals who follow a low-fat or low-carbohydrate diet coupled with lifestyle changes have about the same weight-loss success; however, those who adhere to a low-carb diet may decrease cardiovascular disease risk the diet increases high-density lipoprotein (HDL) cholesterol levels, according to a new study published in the Annals of Internal Medicine.
For the study, researchers followed 307 individuals with a body mass index (BMI) of 30 to 40 kg/m2. Researchers assigned patients to either a low-carbohydrate or a low-fat diet. The low-carb group was instructed to eat no more than 20 grams of carbohydrate per day for three months and then increase by 5 grams per day each week until they achieved their desired weight. The low-fat diet group was told to reduce calorie intake to 1,200 to 1,800 kcal per day with no more than 30% of calories from fat. All 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. Researchers collected information about weight at the start of the diet and after three, six, 12, and 24 months. They also collected information on cholesterol levels, blood pressure, bone density and side effects.
After two years, patients lost an average of 7 kg or 7% of body weight, and no differences between the two groups were found. The low-carb group had greater increases in high-density lipoprotein (HDL) cholesterol levels at all time points, approximating a 23% increase at two years, compared to the low-fat diet group.