For weight loss and for reducing cardiovascular risk, cutting down on carbs was a more effective strategy than limiting fat intake in a randomized trial, researchers found.
At 12 months, individuals on a low-carbohydrate diet had lost 5.3 kg (11.7 lb), while those on a low-fat diet with similar caloric value had lost 1.8 kg (3.9 lb), for a mean difference of -3.5 kg, or 7.7 lb (95% CI minus 5.6-minus 1.4, P=0.002), according to Lydia Bazzano, MD, PhD, of Tulane University in New Orleans, and colleagues.
They also had significantly greater increases in HDL cholesterol, with a mean difference of 7 mg/dL (95% CI 3-11, P<0.001), along with a greater decrease in the ratio of total to HDL cholesterol, with a mean difference of -0.44 (95% CI minus 0.71-minus 0.16, P=0.002), the researchers reported in the Sept. 2 Annals of Internal Medicine.
Previous studies on low-carbohydrate diets and cardiovascular risk have had conflicting results and were limited by a lack of population diversity and the inclusion primarily of patients with the metabolic syndrome or diabetes.
https://www.medpagetoday.com/Cardiology/Prevention/47447
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Effects of Low-Carbohydrate and Low-Fat Diets: A Randomized TrialLydia A. Bazzano, et al
Ann Intern Med. 2014;161(5):309-318.Background: Low-carbohydrate diets are popular for weight loss, but their cardiovascular effects have not been well-studied, particularly in diverse populations.
Objective: To examine the effects of a low-carbohydrate diet compared with a low-fat diet on body weight and cardiovascular risk factors.
Design: A randomized, parallel-group trial. (ClinicalTrials.gov: NCT00609271)
Setting: A large academic medical center.
Participants: 148 men and women without clinical cardiovascular disease and diabetes.
Intervention: A low-carbohydrate (<40 g/d) or low-fat (<30% of daily energy intake from total fat [<7% saturated fat]) diet. Both groups received dietary counseling at regular intervals throughout the trial.
Measurements: Data on weight, cardiovascular risk factors, and dietary composition were collected at 0, 3, 6, and 12 months.
Results: Sixty participants (82%) in the low-fat group and 59 (79%) in the low-carbohydrate group completed the intervention. At 12 months, participants on the low-carbohydrate diet had greater decreases in weight (mean difference in change, −3.5 kg [95% CI, −5.6 to −1.4 kg]; P = 0.002), fat mass (mean difference in change, −1.5% [CI, −2.6% to −0.4%]; P = 0.011), ratio of total–high-density lipoprotein (HDL) cholesterol (mean difference in change, −0.44 [CI, −0.71 to −0.16]; P = 0.002), and triglyceride level (mean difference in change, −0.16 mmol/L [−14.1 mg/dL] [CI, −0.31 to −0.01 mmol/L {−27.4 to −0.8 mg/dL}]; P = 0.038) and greater increases in HDL cholesterol level (mean difference in change, 0.18 mmol/L [7.0 mg/dL] [CI, 0.08 to 0.28 mmol/L {3.0 to 11.0 mg/dL}]; P < 0.001) than those on the low-fat diet.
Limitation: Lack of clinical cardiovascular disease end points.
Conclusion: The low-carbohydrate diet was more effective for weight loss and cardiovascular risk factor reduction than the low-fat diet. Restricting carbohydrate may be an option for persons seeking to lose weight and reduce cardiovascular risk factors.
Primary Funding Source: National Institutes of Health.
