Skip to content

Confused By Healthy & Unhealthy Fats? Here Are 6 Rules To Live By

Eva Selhub, M.D.
October 29, 2018
Eva Selhub, M.D.
By Eva Selhub, M.D.
Dr. Eva Selhub is a resiliency expert, physician, author, speaker, scientist, and consultant. She studied medicine at Boston University and is board certified in Internal Medicine.
Image by Vera Lair / Stocksy
October 29, 2018

When it comes to your health, it's important to get your fat facts straight. And this is easier said than done, as there's a lot of misinformation out there about dietary fat and what's healthy or not. When I was 9 or 10 years old, I remember that we weren't allowed to keep butter or other foods that are high in fat in the house because my dad had heart problems and high cholesterol. I remember we were encouraged to eat egg whites (versus the whole eggs), drink low-fat milk, and use margarine instead of real butter.

Those were the 1980s, when a low-fat diet was the rule if we wanted to lose weight and stay healthy. The hype was widespread until just recently, when new studies started showing that not all fats were bad and that true benefits come from a low-carbohydrate diet, not necessarily one that is low in fat.

This ad is displayed using third party content and we do not control its accessibility features.

Seeing this giant pivot in perspective on fat, it's no wonder that people are now confused. I can't count the number of people who still think they can't eat eggs or that in order to lose weight, they have to follow a low-fat diet, avoiding even healthy fats that come from fish or fish oil. So let's set the fat facts straight. Here are six fat rules to live by:

1. Plain and simple: Your body needs fat to thrive.

Your body absolutely needs fat to function and thrive. It needs fat for fuel, to absorb other nutrients, to help regulate inflammation, movement, and blood clotting, and to make up the membranes that surround the cells as well as the sheaths that cover nerves. In other words, you need fat to thrive.

2. There are different types of fat—and a fat's structure determines how healthy it is.

Whether or not a fat is good for you is dependent on its structure, which then affects its function and how it's assimilated in the body. First, some fats are solid and others are liquid, and all fats do not dissolve in water. All fats have a backbone (or chain) that is made up of carbon atoms, the length of which varies, from short to medium to long. Each carbon atom in the chain binds to another carbon atom and to hydrogen and/or oxygen atoms.

When the four binding sites of each carbon atom are used up, the fat molecule is called "saturated." If there is an empty spot on the chain, it is called "unsaturated." One empty spot deems the fat molecule as "monounsaturated," and multiple empty spots deem it "polyunsaturated." Saturated fats are solid at room temperature, and unsaturated fats are liquid at room temperature. When liquid fats like vegetable oils are turned into solid fats through a process called hydrogenation, they become trans fats.

This ad is displayed using third party content and we do not control its accessibility features.

3. Some fats are very healthy, and some are not healthy AT ALL.

By far, the worst kinds of fats are the man-made trans fats. Any time you see "hydrogenated" or "partially hydrogenated oil" on a label, walk away fast. Common foods that might contain these bad fats include margarine, most processed junk food, packaged cookies, frozen desserts, and pizzas.

Studies have found that consuming trans fats can increase the "bad" LDL cholesterol and lower the "good" HDL cholesterol, which puts people more at risk for heart disease1. Evidence suggests that trans fats may increase the risk of developing type 2 diabetes due to their contribution to insulin resistance. Trans fats have also been linked to increased inflammation and damage to blood vessels2.

Saturated fats have mixed reviews, as some are really healthy and some, not so much. Examples of saturated fats include whole milk products (including cheese and cream), beef fat, bacon fat, red meat, and coconut oil. Though in the past we were told that consuming too much saturated fat would increase cholesterol levels and the risks for heart disease and death, recent studies and meta-analyses have refuted that finding, showing that there was no increase in cardiovascular risks and deaths3. It was concluded, however, that it is best to lower the intake of saturated fat and replace it with unsaturated fats.

As you must have guessed, the "good" fats are the unsaturated fats, or the liquid fats. Examples of monounsaturated fats include avocados, olive oil, sesame oil, safflower oil, and peanut oil. Polyunsaturated fats are found in many foods and oils such as walnuts and almonds; fish like salmon, herring, albacore tuna, Alaskan rockfish, trout, and mackerel; sunflower seeds, flaxseeds and flaxseed oil, safflower oil, and soybean oil.

Image by Pixel Stories / Stocksy
This ad is displayed using third party content and we do not control its accessibility features.

4. Some fats are essential.

Your body is able to make all the fats except two polyunsaturated fats: alpha-linoleic acid (ALA), an omega-3 fatty acid, and linoleic acid (LA), an omega-6 fatty acid. The only way to get these fatty acids is through your diet. Since your body doesn't make them and you intricately need them for normal bodily functioning, like making up the membranes of cells, regulating blood pressure or controlling inflammation, these fatty acids are deemed "essential."  

While omega-6 fatty acids have been found to have some health benefits such as decreasing nerve pain (as happens in diabetic neuropathy) and inflammation, and treating rheumatoid arthritis4, most of the studies have pointed to the benefits of omega-3s. Studies show that omega-3 fatty acids may help in lowering cholesterol, blood pressure, and inflammation, while increasing insulin sensitivity and helping prevent heart disease and stroke5.

Both omega-3 and omega-6 fatty acids are meant to be consumed in equal ratio, synergistically giving the body the essential fats it needs to function at its best. Back in the times before agriculture, when we were hunters and gatherers and our ancestors ate what was naturally available, the ratio of omega-6 to omega-3 was about 1:1. Now, with the advent of agriculture, grains and dairy, processed, man-made and fast foods, however, the ratio has changed to 6:1 (some studies report the ratio in most Western diets is 15:1 to 16.7:1!6).

5. The modern diet has too much omega-6.

Excessive amounts of omega-6 fatty acids (PUFA) and a very high omega-6 to omega-3 ratio—as is found in today's Western diets—is associated with the pathogenesis of many diseases6, including cardiovascular disease, cancer, and inflammatory and autoimmune diseases. It is also associated with asthma, obesity, as well as depression and other psychiatric disorders7.

The food culprits in the modern Western diet that skew the ratio include such foods as French fries and onion rings (and other such fried foods), baked goods such as cookies and muffins, dairy, vegetable oil, eggs, beef, pork, and chicken. These omega-6-rich foods increase the gap in the ratio also because of the low intake of omega-3-rich foods such as fish, flaxseeds, chia seeds, walnuts, soybeans, and canola oil. The higher the intake of omega-6 over omega-3 fish oils, the higher the risk for inflammation8.

This ad is displayed using third party content and we do not control its accessibility features.

6. There is a recipe to optimize fat intake for best health.

The goal is to ensure that your dietary intake of omega-6 fatty acids matches your intake of omega-3 fatty acids as much as possible. In simple terms, optimizing the omega-6/omega-3 ratio in your diet means lowering your intake of processed foods and sugars and eating more fish, vegetables, nuts, and seeds. A simple recipe to follow to optimize healthy fat intake involves the following:

1. Avoid omega-6-rich vegetable oils.

Avoid oils such as sunflower oil, corn oil, soybean oil, peanut oil, and cottonseed oil. Instead, choose oils that are low in omega-6 fatty acids including flaxseed oil or high in saturated fat, like coconut oil, palm oil, butter, and olive oil. 

This ad is displayed using third party content and we do not control its accessibility features.

2. Eat animal foods high in omega-3s, especially seafood.

Currently, the best dietary source of omega-3 fatty acids is from fish oils and fish. You really can't go wrong, though, with seafood, especially fatty fish like salmon, mackerel, and herring, which have the highest levels of omega-3 fatty acids. 

3. Eat nuts and seeds. 

Walnuts, almonds, flaxseeds, and chia seeds (among others) provide the body with a third type of omega-3 fat, alpha-linolenic acid (ALA). ALA is also an essential fat and is used for energy. The body can make EPA and DHA from ALA, but only in limited amounts. In addition, it appears that the conversion of ALA to EPA and DHA is hindered by a high intake of omega-6, which may be one of the reasons a diet high in omega-6 fatty acids is associated9 with poor health outcomes. The bottom line is that you will benefit from eating these nuts and seeds; just try to avoid eating them with foods high in omega-6!

4. Eat your veggies.

Along with nuts and seeds, there are several plant sources for ALA. Such vegetables include some leafy greens like spinach and arugula, sprouted radishes, and cruciferous vegetables like Brussels sprouts, cabbage, broccoli, and cauliflower. Just note that the conversion to EPA and DHA is very small10 and in addition, is dependent on other food intake.11 Your best bet is to eat these veggies with some type of seafood.

Want to turn your passion for wellbeing into a fulfilling career? Become a Certified Health Coach! Learn more here.