Not all types of fat will make you gain weight.
New research suggests that a high-fat Mediterranean diet with extra-virgin olive oil is actually better than a low-fat diet at helping you shed some pounds.
While the study does not give you free rein to eat an entire box of pizza, it does give you the validation to have your breakfast cooked in olive oil instead of butter.
A Mediterranean diet is typically heavy on vegetables, legumes, fruit, fish, whole grains and nuts. Often cooked with olive oil, the diet keeps poultry and lean cuts on the menu, while it excludes processed food, red meat and sugar.
In the randomized control study, researchers looked at the weight and waist circumference of about 7,447 study participants in Spain who consumed three different diets over the course of five years.
About 90 percent of the men and women were obese during the start of the trial. Of this percentage, they either had high cholesterol, type 2 diabetes and high blood pressure, or were smokers.
Each participant was assigned to one of three groups: the first group ate Mediterranean diet with olive oil; the second group ate the same diet with nuts; and the third group consumed a low-fat control diet.
All of the participants received dietary counseling, but were not given advice about exercise.
In the end, all groups lost a little bit of weight, but the first group did the best.
Researchers found that after the duration of the study, participants in the first group and second group lost 0.43 kilograms and 0.08 kilograms respectively.
Those on the second group saw a slight loss of weight during the first three years and then a significant decrease after five years compared with how they started, although it was not very different from the third group.
When it comes to waist size, all groups saw an increase. For the group that ate a low-fat diet, their waist size grew 1.2 centimeters (approximately 0.47 inches), while the olive oil group saw a 0.85-centimeter (0.33 inches) increase. The group that received nuts saw the least increase in waist size at 0.37 centimeters (0.14 inches).
Dr. Dariush Mozaffarian, who wrote an accompanying editorial for the study, says dietary guidelines should lose warnings when recommending cooking with olive oil or eating nuts.
"They don't have caveats with fruits and vegetables but do with fat," says Mozaffarian. "And this study shows we should get rid of that fear of fat."
Details of the study are featured in the journal The Lancet Diabetes & Endocrinology.
Photo: Thomas Ricker | Flickr