Among adults who are obese, a low-carbohydrate diet was more effective than a low-fat diet in reducing weight and CV risk, researchers reported.
Researchers conducted a randomized, parallel-group trial to compare the effects on weight and CVD risk factors of a 12-month low-carbohydrate diet with those of a low-fat diet among adults with a BMI of 30 kg/m2 to 45 kg/m2 (n=148; mean age, 46.8 years; 88% women; 51% black). Participants did not have diabetes or clinical CVD at baseline.
Participants were assigned to a low-carbohydrate diet and instructed to maintain an intake of digestible carbohydrate, defined as total carbohydrate minus total fiber, of <40 g/day or to a low-fat diet and instructed to maintain <30% of daily energy intake from total fat (<7% from saturated fat) and 55% from carbohydrate. They were not given calorie or energy goals and were asked not to change their physical activity levels during their intervention.
Lydia A. Bazzano, MD, PhD, MPH, of the department of epidemiology at Tulane University, New Orleans, and colleagues collected data on weight, CV risk factors and dietary composition at baseline, 3, 6 and 12 months. The intervention was completed by 82% of those in the low-fat group and 79% of those in the low-carbohydrate group.
According to Bazzano and colleagues, compared with those assigned to the low-fat diet, those assigned to the low-carbohydrate diet had the following at 12 months:
- Greater decrease in weight (mean difference in change, –3.5 kg; 95% CI, –5.6 to –1.4; P<.001).
- Greater decrease in fat mass (mean difference in change, –1.5%; 95% CI, –2.6 to –0.4; P=.011).
- Greater decrease in ratio of total cholesterol to HDL (mean difference in change, –0.44; 95% CI, –0.71 to –0.16; P=.002).
- Greater decrease in triglyceride level (mean difference in change, –14.1 mg/dL; 95% CI, –27.4 to –0.8; P=.038).
- Greater increase in HDL (mean difference in change, 7 mg/dL; 95% CI, 3-11; P<.001).
- Greater decrease in Framingham estimated 10-year risk for CHD (mean difference in change, –1.4%; 95% CI, –2.1 to –0.6; P<.001).
There was no difference in reduction of LDL levels between the groups, the researchers found.
“Findings from this trial may offer new evidence for the recommendation of a low-carbohydrate diet to obese persons as an additional nonpharmacologic approach for weight loss and reduction of CVD risk factors,” Bazzano and colleagues wrote.
Disclosure: The study was funded by a grant from the NIH. The researchers report no relevant financial disclosures.