Low-Carb Beats Low-Fat, Diet Review Finds

A new analysis of 17 studies of dietary interventions to promote weight loss and a cardiac benefit found that low-carb diets "were 98 percent more likely to lower the risks of heart attack or stroke" in people who are overweight.

Writing in PLOS ONE, Jonathan Sackner-Bernstein MD and colleagues conducted a Bayesian analysis of weight-loss dietary therapies, using data from 17 randomized controlled trials involving 1,797 participants.

Bayesian analyisis is a statistical procedure used to estimate parameters of an underlying distribution based on the observed distribution. Traditional "frequentist" statistical methods were also used in the team's analysis.

The researchers defined a low-carbohydrate diet as one in which carb intake was limited to 120 gms daily.

Low fat restricted fat intake to 24% of daily calories.

Of the 17 diets studied, 7 showed statistically significant weight loss with low-carb compared to low fat diets. None of the 17 studies showed that patients on low-fat diets lost more weight than patients on low-carb diets..

The analysis showed that low carbohydrate diets resulted in 2 kg more weight than low-fat diets and "significantly lower predicted risk of atherosclerotic cardiovascular disease events".

Patients who adhered to either type of diet lost weight and had improvements in cardiac risk factors.

"By Bayesian modeling, the likelihood that low-carbohydrate diet was associated with greater improvement in predicted risk compared with low-fat diet was at least 08.1%," the team noted.

The probability of risk reduction with low-carb diet varied. It was 82% in lower-risk African Americans and 92% in higher risk whites. Low fat's associated with risk reduction ranged from 62% in lower risk African American and 72% in higher-risk whites.

The study was funded by Atkins Nutritionals, which advocates high-fat, high-protein diets. The authors said the funders had no role in study design, data collection or other aspects of the article's preparation and publication though they were paid for their work.