Fat is back, new research shows.
This latest study, released Monday in the new edition of Lancet Diabetes & Endocrinology, does not give you free reign to chow down on pizza or to have that second dessert, but it does give you license to have that egg for breakfast if you cook it in olive oil, rather than butter, and forgo the side of bacon or toasted white bread.
from scientists looking at the weight and waist circumference of 7,447 people who ate three different diets for five years in a randomized control study — suggests that a Mediterranean diet (versus a low-fat diet, in which you avoid all fat) is more successful in helping you lose a little weight. This is true even if you are older, have type 2 diabetes or are already obese or overweight.
A Mediterranean diet — one of the recommended options with the updated dietary guidelines — is heavy on vegetables and legumes, fish, fruit, nuts and whole grains. The food is cooked with olive oil. Carnivores on the diet keep poultry and lean cuts of meat on the menu. Red meat, processed food and sugar are off the table.
Researchers figured this out by comparing data from men between the ages of 55 and 90 and women between 60 and 80 years old. About 90% of the people in the study were overweight or obese when they started the trial and either had type 2 diabetes or had high cholesterol or high blood pressure or were smokers.
Scientists split the people into three groups; one stuck with a Mediterranean diet and was given extra-virgin olive oil donated by an olive oil company to cook their meals. Another group ate a Mediterranean diet and was given a mix of nuts by a nut company to add to their diets. Another group was advised to avoid all dietary fat. Each group was given some dietary counseling through the five years of the study. None of the groups was given advice about exercise.
All three groups lost a little bit of weight. The group that was given the extra-virgin olive oil and ate the Mediterranean diet did the best. There was a significant weight loss at both the three- and five-year mark compared with the group eating the low-fat diet. This group lost about 2 pounds, while the low-fat group lost 1.3 pounds.
Those who ate more nuts along with the Mediterranean diet saw a slight loss of weight after three years and what was considered a significant decrease at five years, compared with where they started, but it was not very different from the low-fat group.
Waist size did go up slightly for all three groups. The low-fat dieters saw the biggest increase, of 1.2 centimeters (about 0.47 inches), compared with 0.85 centimeters (about 0.33 inches) for the olive oil group. The group that got extra nuts went up the least: about 0.37 centimeters (about 0.14 inches).
The ultimate takeaway from this study was that the fat found in the Mediterranean diet — olive oil, fatty fish, nuts — isn’t bad for you at all.