Healthy Fats and Unhealthy Fats – What is the Difference?

 In Blog

We hear and read “eat healthy fats”. What are healthy fats? What are unhealthy fats? Why does it matter? Here is what you need to know.

Fats are important

In digestion, our bodies break down food into three macro-nutrients: carbohydrates, protein and fat.

  • Carbohydrates break down into glucose molecules as our main source of energy.
  • Proteins break down into amino acids for rebuilding bodily structures and muscles.
  • Fats line our cell walls and help with transport of substances in and out of our cells. Fat is essential for transporting vitamins A, D, E, and K. Fat is important for hormone function, nerve transmission and protecting our organs.

The Problem

A lot of dietary fat attention has focused on heart health. The root of the problem, however, may be inflammation. There seems to be a relationship between chronic inflammation and obesity, insulin resistance, stress, heart disease and other chronic disease.

Inflammation is the body’s way of blocking and destroying invaders and allowing the body to heal, for example, when you cut yourself. Acute inflammation is a good thing. Chronic inflammation, on the other hand, is not a good thing. In chronic inflammation, the body may perceive invaders and eventually attack healthy tissues and organs. This may lead to immune system problems, cancer, heart disease, irritable bowel syndrome, acne and dementia.

Diet is one area we can control that can either fight or cause inflammation. Generally speaking, we want to eat a diet high in whole plant-based foods with fiber, healthy fats and anti-inflammatory properties to control blood sugar levels and promote healing in the gut. Avoid processed foods, unhealthy fats and added-sugar foods.

So, how do we know the difference between healthy fats and unhealthy fats?

Healthy Fats

Monounsaturated Fats

Healthy Fats are monounsaturated fats found in foods such as olives, avocados, nuts, seeds and extra virgin olive oil. This type of fat does not raise LDL (bad) cholesterol or cause inflammation. Replacing some excess carbs with monounsaturated fats helps improve blood sugar control, HDL cholesterol and triglyceride levels (a type of blood fat). Cold-pressed extra virgin olive oil is the oil with the highest amount of monounsaturated fat and lowest amount of omega-6 fat.


Another type of healthy fat is omega-3 polyunsaturated fat. It helps to calm inflammation. We absolutely need it in our diet, although we don’t need it in large amounts and may be harmful if supplemented in high doses. Omega-3 is best consumed from eating whole foods, namely, cold-water fatty fish such as salmon, herring and sardines. Algae is a good plant-based source of omega-3. Other plant-based sources of omega-3 include seeds such as chia, hemp, flax, pumpkin and walnuts. These plant-based sources are a form of alpha-linoleic acid (ALA) which the body has to convert but is not very efficient at doing so. It is good to have chia, hemp, flax, pumpkin, walnuts and dark leafy greens in our diets, but we are best off to also have some fish.

Unhealthy Fats

Trans Fats

Without a doubt, industrially-produced partially hydrogenated trans fats are unhealthy. Trans fats lower the good HDL cholesterol and raise the bad LDL cholesterol. Producers used to use these fats to prolong shelf stability in products. Canada now has a ban on partially hydrogenated products. Check the labels though! Producers can claim “trans fat free” if the product has less than 0.2 grams of trans fats per serving. Steer clear.


Another type of fat that promotes inflammation is too much omega-6 polyunsaturated fat. I say “too much” because, although it is an essential fat, in the sense that our body cannot make it, it is abundant in our foods, and we err on having too much of it. According to dietitian Desiree Nielsen, author of Un-Junk Your Diet: “While there is still some controversy in the scientific literature, I am convinced that we need to lower our intake of omega-6s stat.”

Vegetable grain/seed oils such as corn, soy, canola and sunflower are higher in omega-6 versus other fats. As a result, many of our processed, packaged and fast foods containing these oils are also high in omega-6. Omega-6 is in our meat because animals are fattened up quickly with grain, rather than allowed to graze slowly on grass.

Saturated Fat

Lastly comes saturated fat. Saturated fat is found in meat and dairy. It is typically solid at room temperature. Saturated fat may not be as bad as we used to think. It may raise the bad LDL cholesterol, but it also raises the good HDL cholesterol, and the link to heart disease is not clear. After all, it is a naturally occurring fat. The problem is, the North American diet tends to be overwhelmed with saturated fat. Too much saturated fat may be pro-inflammatory which can lead to other issues. It is wise therefore, watch your saturated fats and eat plenty of vegetables to keep inflammation at bay.

Isn’t canola oil “heart healthy”?

Consider how much processing it must take to squeeze the oil out of a grain of canola verses an olive. Unless you can find cold-pressed oils, most vegetable seed oils are RBD oils (refined, bleached and deoderized). One possible concern with is this is the use of a solvent called hexane to extract the maximum amount of oil from the seed. Another concern is that heating, bleaching and deoderizing oil causes trans fats and also reduces omega-3 content.

The reason why canola producers claim canola oil to be heart healthy, is they are referring to the 2012 Health Canada labeling policy specifically involving vegetable oils. This policy allows food products to claim that “replacing saturated fat with unsaturated fat helps reduce cholesterol”. And it states they can claim “high cholesterol is a risk factor for heart disease”. Again, the link to heart disease is not clear. Not all people with high LDL get heart disease. Not all people with low LDL avoid heart disease. And sure, we should eat more unsaturated fat, specifically monounsaturated fat, like extra virgin olive oil. But canola producers promote canola because it has the recommended 2:1 ratio omega-6 to omega:3. The best place to get your omega-3’s is from cold-water fish, not highly processed, treated canola oil.

Here is a chart showing the different percentages of fats in oils.

Dietary fat in oils

In general, use oils sparingly, about one or two teaspoons for cooking. Use cold-pressed extra virgin olive oil in salad dressings. Get your healthy fats by eating whole foods. This will give you fiber and micro-nutrients to go along with the fats.

Dietary Fat Guidelines

A generally agreed upon healthy amount of total fat is about 30% of total daily calories.

Health Canada recommends an upper limit of 10% of total calories for saturated fats.

That would leave 20% of total calories for unsaturated fats. This is consistent with Health Canada’s recommendation of having more unsaturated fats and less saturated fats.

However, there is a problem with lumping all unsaturated fats together as equal… There is also an upper limit for polyunsaturated fats!

The Food and Agriculture Organization of the UN recommends an upper limit of 11% for polyunsaturated fats (with an upper limit of 9% omega-6 and 2% omega-3).

Do you see this? Omega-6 has a 9% daily caloric limit. Omega-6 is “less allowable” than saturated fats!

The remainder of fat intake should be monounsaturated fat, which should be at least 10% or more. There is no upper limit for monounsaturated fat, other than the general 20 – 35% total fat daily reference intake. It would be better to have more than 10% monounsaturated fat and less than 11% polyunsaturated fat.

So how do we know how much of each type of fat we are eating?

Food Labels

oreo cookie ingedientsIn Canada almost all packaged food labels must have an ingredient list and a nutrition facts table. The nutrition facts table lists the total fat per serving, as well as the breakdown of saturated fat and trans fat. The remaining fat, which is not listed, is unsaturated fat. Food manufacturers do not have to list unsaturated fats in the nutrition facts table. However, I would find it much more helpful if they did! I would like to see the breakdown of monounsaturated, omega-6, and omega-3 on all products. This would help us to know how much polyunsaturated omega-6 versus monounsaturated fat we are consuming. Remember, we want more monounsaturated and less omega-6.

Since the nutrition facts table does not show the break down of unsaturated fats, we need to read the ingredients list. Does the food have vegetable seed oil like corn, canola or soybean oil? Then the product likely has polyunsaturated omega-6 fat.

In Summary

We will make better choices by eating foods that don’t come with a package or box or label at all. Avoid packaged cookies, crackers, potato chips, baked goods, deep-fried foods such as french fries, and junk food in general.

Eat whole foods! Eat lots of raw or lightly steamed fresh vegetables, berries, different colours of fruits, avocado, unroasted nuts, seeds and beans, free-range meat and poultry, and fish.

Read our blog on Canada’s Food Guide Canada’s New Food Guide

Recommended Posts