How Dietary Fat Impacts Your Mental Health

With today’s fad diets and ever-changing recommendations for what you should and should not eat, it can be challenging to know what is evidence based, what’s not, and what is right for your body in particular. One of the fallbacks of so much dietary advice is that people can end up cutting things out that in fact provide the body with essential nutrients. Today we embrace fat, which, after having been blacklisted over half a century ago, is experiencing somewhat of a comeback.

Up until recently, many popular diets viewed fat as unfavorable, often operating under the false assumption that “fat makes you fat.” Popular opinion is starting to change on this front however, as the body of research on fat grows and we (physicians, mental health providers, nutritionists, you and me) continue to learn just how complex the body’s relationship to fat is. It is simply not reasonable nor healthy to boil one’s relationship with fat down to simple avoidance, as tempting as that black and white approach may be! Keep reading to learn more about how to incorporate the right fats for optimal mental health benefits.

Fat - Facts and Fictions

There are four broad categories of fat: trans, saturated, monounsaturated, and polyunsaturated. Most trans fats are artificially made using an industrial process and can be found in products like margarine, packaged snack foods, and frying oils. Trans fats should be avoided at all costs as research has shown them to cause increased risk for heart disease, stroke, and type two diabetes.

Up until recently most research indicated that saturated fat should also be avoided, however, a recent extensive and groundbreaking study reveals that saturated fat actually does more good than harm for most people. In that study, consuming either saturated or unsaturated fats was associated with a lowered risk of stroke, heart attack, and death.

The less risky and more helpful fats are the polyunsaturated and monounsaturated fats. Fat is an excellent source of energy, it is important for absorption of fat soluble vitamins, and it is a critical component in each of our cells. Fats play a role in brain health as they are structural components of brain cell membranes and influence the functioning of the brain cells. Omega-3 fatty acids are particularly important to brain and body health. As a bonus, fats also keep skin soft.

It is true that fat can play a role in being overweight and too much of the wrong fats has been shown to contribute to certain diseases, but the “fat makes you fat” mantra is largely false. In fact, when the general public was instructed to limit fat intake, rates of overweight and obesity started to climb - not fall.

History of Fat Consumption and the “War on Fat”

Fat has likely always been a part of the human diet. Fat sources for hunter gatherer societies would have been comprised of both vegetable and animal sources and included things like nuts, meat and fish. Fat, being the more calorie dense than protein or carbs, was useful for the high energy demands of the hunter gatherer lifestyle.

The modern war on fat began in the 1940s when a small group of scientists claimed that there was a causal relationship between high-fat diets and high cholesterol. Their claim suggested that the fat intake contributed to the rising rates of heart disease in the US.

When Americans started eating less fat in the 1980s, we started eating more sugar and a public health crisis soon ensued. It turns out that, by and large, sugar is much more toxic to consume than healthy fats, leading to diseases like obesity and type II diabetes,  Source:

When Americans started eating less fat in the 1980s, we started eating more sugar and a public health crisis soon ensued. It turns out that, by and large, sugar is much more toxic to consume than healthy fats, leading to diseases like obesity and type II diabetes,


Fear that fat was to blame for the rising rates of heart attack and heart disease opened the door for food manufacturers to create an entire industry devoted to low and no fat products. Smart marketing convinced consumers that buying this or that low fat product would allow them to minimize fat intake and reduce their risk for a host of diseases. The problem was, the science wasn’t there to back these claims and the lack of regulation of the food industry allowed for a variety of health claims on foods that were not backed by science. The result was a false sense of security among the general public and an influx of hundreds of low-fat and no-fat food products which, despite being branded as healthy, contained chemical additives, sugar, sugar substitutes, trans fats, and other ingredients that would prove to have health risks of their own.

Over the last 70 years, rates of being overweight or obese have actually increased almost exponentially. Now, the newer research described above suggests that not only should we be eating fat, but when fat is cut out, risk increases for higher weight and disease. Fat has also been proven to play a role in good mental health.

Although the low fat diet recommendations have been shown to be unfounded, the public health crisis triggered these faulty guidelines continues. From the 70s to today, we have witnessed a large scale experiment on changing the types of dietary fats eaten by the US population and the results of the experiment are not good, as the rates of obesity and type 2 diabetes increased dramatically.

Current Practices with Fat

A significant factor in the obesity epidemic is portion size. Americans are simply eating more calories than ever before. Even though fat is calorie- dense, because it tastes good and because there is more of it on our plates, it is easy to eat too much of it.

Research published over the last 60+ years shows that fat is an important part of a healthy diet. Dietary guidelines currently recommend that adults should receive 20%-35% of their daily calories from fat. When people do not get enough fat, often seen in those who restrict to a low-fat, low-calorie diet, the risk for health problems increases. Yet, you may wonder, if fat is so important, helpful, and necessary, then why are so many Americans having weight problems?

Well, the problem is not fat itself but the amount of food we eat, and the types of fats and carbs we eat.

One Approach—The Mediterranean Diet

So, we have learned that fats are an important part of a healthy diet. However, too much fat and intake of the wrong fats can lead to health problems such as obesity, high cholesterol, heart disease, and diabetes. This means that the goal needs to be intake of the right sorts of fats in moderation. One great example of a well-balanced diet is the Mediterranean diet.

Modeled after the eating patterns of Mediterranean populations, this diet primarily consists of the following:

  • 5 or more servings of vegetables and 2 servings of fruit per day

  • whole grains

  • nuts

  • fish or poultry in small doses

  • limiting red meat consumption to just a few times each month

  • use of herbs and spices

  • lots of olive oil

  • moderate amount of red wine daily

This diet emphasizes foods that contain the good fats, such as fish, nuts, and olive oils. It also de-emphasizes foods that have the less healthy fats. The Mediterranean diet is well-regarded in the medical community because it the demonstrated health benefits in many research studies. Research shows that the Mediterranean diet helps to lower “bad” cholesterol (LDL), reduces the risk of heart disease, lowers the risk of cancer, and may even help to prevent dementia because it protects brain health.

Other Lifestyle Choices

Your overall health depends on many different factors. Each dietary choice should be just one part of a broader health plan. If you choose to follow the Mediterranean diet for example, it does suggest consumption of fruits, vegetables, healthy grains, fish, poultry, and meats. See also the previous article in this series highlighting the role of meats, including occasional red meat, for mental health. Ultimately, you need a varied diet that includes fats along with other vitamins and nutrients for optimal wellness.

Of course, other lifestyle choices are also important for your physical and mental well-being. For example, daily exercise and activity is equally important to brain and body health. Being active also helps to maintain weight, which is what many people worry about when they think about consuming fats. Avoiding or stopping smoking is also essential for optimal overall health.

Final Recommendations

Today’s research continues to tell us more and more about the links between diet and health. Your diet affects your physical health and your mental health too. When it comes to eating fats, you may have been avoiding them, thinking you were doing the best thing for your health; however, fats are a necessary part of a healthy diet. By selecting the right foods, with the right types of fats, and by making good lifestyle choices, you can promote your mental health and maintain good physical health.

Everyone is unique, and everyone has their own specific health and nutritional needs. If you need specialized advice for your physical and mental health, consider consulting with an integrative or functional medicine psychiatrist or doctor. Ask your provider to help you develop a holistic dietary plan that will be optimal for promoting your physical and mental health.