Eating vegetables fats found in foods such as nuts and olive oil does not lead to weight gain. On the contrary, it aids in losing weight. A new study, published in The Lancet on 6th June, found that a healthy fat-laden Mediterranean diet is a better option for weight loss than a low-fat diet. Based on the results, the authors suggest that a diet should not be restricted on the basis of calories and that weight can be managed by making healthier food choices.

Current health guidelines for losing and maintaining weight suggest that interventions such as calorie counting or restrictions on food portions are the only ways to lose extra body weight. The current study, however, believes that such guidelines have been creating an unnecessary fear of healthy fats. In fact, healthy fats in a Mediterranean style diet prove to be more helpful than harmful.

High-fat Mediterranean Diet On Body Weight

A Mediterranean diet can be defined as a diet rich in vegetables and olive oil along with restricted consumption of meat proteins, and it is believed to amplify health benefits. The vegetable fats usually found in a Mediterranean diet are ‘unsaturated fats’ known for their LDL cholesterol-lowering ability in the body. Olive oil is especially naturally supplemented with monounsaturated fats and polyphenols which act as free-radical scavengers in the blood.

It is often believed that foods having high level of fats are more likely to increase body weight. This perception has led many to avoid high-fat foods when trying to lose weight.

 Most of the time, health professionals such as doctors and dietitians, do not recommend foods with a high fat content to overweight or obese people, even if the fats are healthy. The current study dissuades all such perceptions. According to the researchers “an unrestricted-calorie, high-vegetable-fat Mediterranean diet” leads to weight loss rather than weight gain in the long-term.

The multicenter clinical trial study called PREDIMED was carried out at 11 hospitals in Spain. Dr. Ramon Estruch, of the University of Barcelona was the lead author of the study.

Older people at an increased risk of heart diseases or with type II diabetes were recruited for the study and a wide majority i.e. 90% of them was overweight or obese. A total of 7447 subjects were included in the study, with men between the ages of 55–80 years and women between the ages of 60–80 years.

Three groups were made; one was given a Mediterranean diet enriched with extra-virgin olive oil, the second was given a Mediterranean diet containing nuts while the third received a normal control-diet low in dietary fats.

The third group was also set up as a control group to see the effects of elimination of all fats in contrast to healthy fats. Any recommendations on energy consumption or physical activity i.e. exercise were not set. The subjects of the PREDIMED trial were measured for body weight and waist circumference every year for five consecutive years.

After nearly 5 years of the intervention, the people with Mediterranean diets that were consuming olive oil had an average 0.43 kg mean decrease in body weight, meaning they lost nearly 2 pounds. Meanwhile the group consuming a Mediterranean diet with nuts had a mean decrease of 0.08 kg in body weight, meaning they lost 1.3 pounds compared to the low-fat diet control group.

“More than 40 years of nutritional policy has advocated for a low-fat diet, but we’re seeing little impact on rising levels of obesity,” said Estruch. “Our study shows that a Mediterranean diet rich in vegetable fats such as olive oil and nuts had little effect on body weight or waist circumference compared to people on a low-fat diet. The Mediterranean diet has well-known health benefits and includes healthy fats, such as vegetable oils, fish and nuts.”

Although the research has clarified some views on the role of healthy fats and weight management, there were some limitations involved. The researchers agree that not all ‘fats’ can be deemed equal and while some are beneficial, others can be harmful. Healthy fats differ from unhealthy fats (saturated fats) usually found in processed foods.

“Our findings certainly do not imply that unrestricted diets with high levels of unhealthy fats such as butter, processed meat, sweetened beverages, deserts or fast-foods are beneficial,” Estruch added.

Furthermore, the original aim of the study was to determine the effects of a Mediterranean diet rich in healthy fats, on body weight and waist circumference. Although the study saw an overall decrease in the body weight of the subjects there was an increase in their waist circumference, but less in the individuals on the healthy fats diet.

The people in the low-fat group showed a half-inch i.e., 1.2 cm increase in their waist size, while the people in the olive oil group only had a one-third of an inch increase i.e. 0.85 cm in waist. Members of the Mediterranean diet with nuts only saw a mere 0.14 inches equal to 0.37 cm increase in waist circumference.

Ultimately we need to make wiser choices about the type of fats we eat and not on how much fat we eat.