If I Eat a Diet High in Healthy Fats, Do I Need to Worry?

Avocado toast
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In short—no. In fact, it would be a shame if concern over healthy fats deterred you from this healthy way of eating.

Fat is an essential part of a healthy diet. It is a source of energy, plays a part in the absorption of many vitamins, provides insulation for our bodies, and contributes to the structure of cells. However, the association of some fats with an increased risk of heart disease, and concern over the high number of calories per gram of fat, has resulted in widespread advice in recent years to adopt a low-fat diet.

That said, we know that the food and lifestyle traditions of the Mediterranean—where a relatively high intake of healthy, unsaturated fats, especially from plant sources, are an integral part of the local diet—have been shown to reduce the risk of many illnesses, including heart disease and cancers. In this part of the world, an increase in obesity and chronic disease coincides with areas where people are moving most quickly away from their traditional diet to a culture of processed foods.

Evidence from the Predimed Study, a particularly well-designed study that adds to considerable observational data, has demonstrated that the traditional Mediterranean diet, supplemented with extra virgin olive oil or nuts, has a powerfully positive effect on health.

In fact, U.S. Dietary Guidelines now suggest that “dietary advice should put the emphasis on optimizing types of dietary fat and not reducing total fat.” This recognizes that unsaturated fats are beneficial, especially when they replace other, less healthy fats, such as saturated fats and trans fats.

All Fats Are Not the Same

The unsaturated fats that predominate in the Mediterranean diet have been shown to be healthy. The monounsaturated fats that are in abundance in olive oil, and the combination of mono- and polyunsaturated fats in nuts, for example, lower potentially harmful levels of LDL cholesterol.

Furthermore, at least some of the benefits of eating oily fish, another staple of the diet, may derive from the high levels of omega-3 polyunsaturated fats.

Saturated fats are kept to a minimum in the Mediterranean diet, where vegetables and whole grains are eaten regularly and meat is consumed much less frequently. Still, saturated fats are also not all the same, and there is increasing interest in the possibility that medium-chain saturated fats in fermented dairy products, such as cheese and yogurt from free-roaming goats and sheep in the Mediterranean, may be less harmful than the processed dairy available in most supermarkets in the United States and Europe.

But Won’t Too Much Fat Make Me Fat?

Our bodies do not simply add up the calories in foods, take away the calories burned, and transport the rest to our waistlines. Despite what the name implies, fat in our diet is not the simple cause of us becoming fat.

Although we do know that portion size and exercise are important factors in weight control, there is increasing understanding that the effects of combinations of different nutrients on blood sugar and insulin levels are perhaps more important than counting calories.

A Mediterranean diet of healthy fats has been shown to compare favorably to other diets, including low-fat diets, when it comes to weight loss.

Think Beyond the Fat Content

Of course, we do not eat nutrients in isolation. It is much more useful to consider whether the fats we consume are contained in natural, wholesome foods, and what other nutrients are in those selections. For example, nuts are an excellent source of fiber, vitamins, and minerals, as well as healthy fats. Fish is an excellent source of protein and calcium, in addition to omega-3 fats.

The most ubiquitous fat source in the Mediterranean diet, of course, is extra virgin olive oil. Not only does it contain a high proportion of healthy monounsaturated fats, but it is also rich in vitamin E and polyphenol antioxidants. These antioxidants, including some of which are unique to extra virgin olive oil, may have a particular role in preventing a process called oxidation of cholesterol, which is thought to be a pivotal step in developing illnesses such as heart disease and stroke.

The importance of these antioxidants exclusively in extra virgin olive oils has been recognized by the European Food Safety Authority, and oils with particularly high levels of these compounds can carry a health claim in European nations. High levels of these beneficial antioxidants can be identified in extra virgin olive oils that have a peppery flavor, so it is definitely worthwhile to acquire a taste for olive oil.

A Word From Dr. David L. Katz
Verywell Senior Medical Advisor and True Health Initiative Founder

Diets associated with optimal health outcomes—longevity and vitality—all around the world have something very important in common and are otherwise quite diverse. What they share is an emphasis on minimally processed foods, most notably plants (vegetables, fruits, whole grains, beans, lentils, nuts, and seeds), and water for thirst. They are diverse with regard to many details, but important among them is the level of different macronutrients, especially fat and carbohydrate. 

Some of the world’s most healthful diets, as described here, are quite high in fat; some are quite low. None is high in saturated fat. The takeaway, as ever, is that an emphasis on wholesome foods in sensible combinations is far more important than focusing on the level of a given macronutrient.

Sources:

Estruch R, et al. Effect of a high-fat Mediterranean diet on bodyweight and waist circumference: a prespecified secondary outcomes analysis of the PREDIMED randomised controlled trial. The Lancet Diabetes & Endocrinology. Volume 4 , Issue 8, 666-676.

Office of Disease Prevention and Health Promotion. 2015–2020 Dietary Guidelines for Americans. https://health.gov/dietaryguidelines/2015/

Predimed. Prevencion con Dieta Mediterranea. http://www.predimed.es/

Shai I, et al. Weight loss with a low-carbohydrate, Mediterranean, or low-fat dietN Engl J Med. 2008; 359(3): p. 229-41.

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