Mediterranean Diet Better Than Low-Fat Diet for Weight Loss?

In an effort to assess the long-term effects of ad libitum, high-fat, high-vegetable fat Mediterranean diets on body weight and waist circumference in older individuals at risk of cardiovascular disease (most of whom were overweight or obese), the authors analyzed data of 7,447 asymptomatic men and women who had type 2 diabetes or 3 or more cardiovascular risk factors.

Participants in the study were randomly assigned with a computer-generated number sequence to 1 of 3 interventions: Mediterranean diet supplemented with extra-virgin olive oil; Mediterranean diet supplemented with nuts; or a control diet. Energy restriction was not advised, the investigators noted, adding that physical activity was not promoted.

After a median of median 4 to 8 years of follow-up, participants in all 3 groups had “marginally reduced body weight and increased waist circumference,” according to the investigators. Overall, total fat intake had reduced from 40% to 37.4% in the low-fat diet group, while total fat intake went up from 40% to 41.8% in the cohort adhering to a Mediterranean diet augmented by extra-virgin olive oil. That number went from 40.4% to 42.2% in the nut group, while both Mediterranean diet groups saw a reduction in the percentage of calories consumed from protein and carbohydrate.

While participants in all 3 groups lost weight over the follow-up period, those on the olive oil-rich Mediterranean diet lost the most, at an average of 0.88 kilograms, in comparison to 0.60 kilograms for those following the nut-laden Mediterranean diet. Those in the low-fat diet group averaged weight loss of 0.40 kilograms over that time. All the groups also experienced an increase in waist circumference, with the low-fat diet group seeing an average increase of 0.37 centimeters in that span.

“We have demonstrated that Mediterranean diet reduces cardiovascular risk by 30% without changes in body weight or waist circumference,” says Ramon Estruch, MD, from the faculty of medicine at the University of Barcelona, and lead author of the study.

“Mediterranean diet,” says Estruch, “is the best weapon we have to fight against cardiovascular disease and, despite their vegetable fat content, people do not increase adiposity.”

—Mark McGraw

Reference:
Estruch R, Martinez-Gonzalez M, et al. Effect of a high-fat Mediterranean diet on bodyweight and waist circumference: a prespecified secondary outcome analysis of the PREDIMED randomized controlled trial. The Lancet: Diabetes & Endocrinology. 2016.