According to a new study, a low-carbohydrate diet is more effective than low-fat diets for weight loss and reducing cardiovascular risk factors.
To compare low-carbohydrate vs. low-fat diets on body weight and cardiovascular risk factors, the researchers randomly assigned 148 men and women without clinical cardiovascular disease and diabetes to follow a low carbohydrate (less than 40 grams per day). Low fat diet (less than 30 percent of daily calories from fat).
All participants were classified as obese on the basis of body mass index and more than half of the participants were black.
Both the low-carbohydrate and low-fat groups received dietary counseling at regular intervals but did not target any specific calories or energy.
At 3, 6, and 12 months, participants on a low-carbohydrate diet lost more weight than those on a low-fat diet.
At 12 months, people in the low-carbohydrate group lost an average of 7.7 pounds (3.5 kg) more than in the low-fat group.
Although participants in the low-fat group had a larger reduction in their waist size at 3 and 6 months, there was no difference at 12 months.
Overall, blood levels of certain fats predicting the risk of cardiovascular disease in the low-carbohydrate group also decreased.
Physical activity was similar in the groups throughout the study, suggesting that participants in the low-carbohydrate group lost more weight because they did not exercise more.
When the researchers evaluated black and white participants separately, the results were similar.
The study was published in the journal Annals of Internal Medicine.