Learning the difference between good fats and unhealthy fats is key to a balanced diet.

It’s not a secret that consuming too much fat can contribute to an unbalanced diet and excess calorie intake. But did you know that fats are a nutrient needed by the body? Not all fats are created equal, and the type of fats you eat is more critical than the amount of fats. Understanding how they differ is important to make good choices as part of a healthy diet.

Several years ago, I remember my mother going out of her way to buy food that was labelled ‘low fat’ or ‘fat-free’. Fat-free salad dressing. Fat-free cereal. Even fat-free candy. It seemed like the words ‘fat-free’ or ‘low fat’ were slapped across all sorts of products in big, bold letters – even foods where the fat content doesn’t really matter (candy).

My mother’s heart was in the right place. She was trying to buy healthier foods and snacks for her family and likely assumed that less ‘fat’ means less bad stuff.

What my mother didn’t know then and many people still don’t today, is that ‘fat’ is not necessarily bad.

The term ‘good fats’ has wormed its way into our lexicon through food blogs and health content, and while many people likely scoffed at what they thought was an oxymoronic fad of a phrase: they were wrong. There are good fats. And learning the difference is key to a balanced diet.

Fats are actually an essential part of the human diet and have several functions in the body. They help support cell function and give the body energy.  The body also gets essential fatty acids from fats, and they help the body absorb important nutrients such as the fat-soluble vitamins A, D and K. Fats also aid in the production of some important hormones.

Types of dietary fats

The three main fats found in food are unsaturated fats, saturated fats and trans fats.

Trans fats are the bad one. Artificial or industrially produced trans fats to be more specific. They are produced through a process called hydrogenation that is used to turn liquid vegetable oils into solid fats. Artificial trans fats have no known health benefits and increase the risk of heart disease by raising ‘bad’ cholesterol (LDL) levels and should be avoided.

The good news is, you shouldn’t see artificial trans fats anymore because in 2018 Health Canada introduced a ban on partially hydrogenated oils – the largest source of industrially produced trans fats in food – and they were to be phased out of the supply chain in 2020.

There are also natural, or ruminant trans fats which occur naturally in animals and are not formed through hydrogenation. These trans fats make up a small portion of the fats in meat and dairy products. The evidence is inconclusive regarding the health effect of natural or ruminant trans fat.

Unsaturated fats are healthy fats that include monounsaturated and polyunsaturated fats. They are what people usually mean when referring to those ‘good fats’ because they can help reduce ‘bad’ cholesterol and lower your risk of heart disease.

Sources of unsaturated fats include nuts, seeds, avocado, fatty fish, vegetable oils and soft margarine.

Monounsaturated fats are particularly found in safflower, olive and canola oils, avocado, almonds, pecans and sesame seeds.

Polyunsaturated fats include omega-3 fatty acids and omega-6 fatty acids. These are essential fatty acids that the body cannot make on its own and need to be obtained through foods. Omega-3 fatty acids are naturally present in some foods and found in high concentrations in fatty fish like salmon and sardines, flaxseeds, chia seeds, walnuts, canola and soybean oils. Omega-6 fatty acids can be found in vegetable oils like corn and soybean oils.

Saturated fat, the last of the three types of fats, has been the subject of some debate. Usually found in animal-based foods such as fatty cuts of beef, pork, poultry, full-fat dairy products and eggs, saturated fats are also found in some plant-based oils like coconut and palm oils.

Dietary guidelines recommend limiting foods that contain saturated fats because they can raise the level of ‘bad’ cholesterol in blood. While there is evidence that replacing saturated fats with polyunsaturated fats is associated with positive heart health outcomes, the link between saturated fat itself and heart disease is disputed by scientific experts. A 2021 systematic review and meta-analysis has also concluded that dairy fat intake is associated with a lower risk of cardiovascular disease (heart disease and stroke).

What about dietary cholesterol?

We know that cholesterol present in foods has little effect on blood cholesterol levels, contrary to popular belief. As such, in generally healthy individuals with no pre-existing conditions, cholesterol consumed through foods will not lead to increased blood cholesterol.

Considering the food source or ‘food matrix’

More and more, researchers are arguing that the food source of nutrients is more important to consider than the nutrient itself. Indeed, we eat foods and not nutrients per se. Advances in research have demonstrated that foods represent complex matrices of nutrients and other components, with different physical and nutritional structures. Foods are more than the sum of their individual components and studies highlight the importance of focusing on whole foods, or the ‘food matrix’, as opposed to single nutrients such as saturated fats.

“Foods are more than an ingredients list, the number of calories or nutrition facts in a table,” says Maryam Naslafkih, R.D., “Nutrients interact with each other and often work better together than individually.”

For instance, several foods that contain saturated fats or cholesterol, such as eggs and dairy, are very nutritious and provide several health benefits.

“When looking at an egg, the egg white is mostly protein. The egg yolk contains saturated fats and cholesterol, but also vitamins and minerals,” says Naslafkih, “Those fats also help with satiety, and eating one whole egg provides a perfect balance of protein, fat and calories.”

Fermented milks like yogurt contain live cultures that help increase the diversity of gut microbiota – an important part of gut health and overall health. Greek yogurt is also satiating, high in protein and a source of calcium.

Similarly, eggs are nutrient-dense food that provides protein and many vitamins and minerals.

Striving for a healthy diet

Part of maintaining a balanced diet is preferring whole foods that are rich in different essential nutrients. That also means opting for foods that contain unsaturated fats instead of saturated fats whenever possible, considering that certain foods, like fried foods, processed meats, cakes and cookies can be high in saturated fats, while having little nutritional value.

If we think about my Mum back at the grocery store worrying about fat content, it is worth recognizing that fats have a key role to play in terms of taste and texture. ‘Low fat’ or ‘fat-free’ can also mean tasteless. So, to compensate for the sensorial properties of fats, some companies may sometimes add things like sugar, salt or refined carbs to their product. Some foods might be ‘low fat’ or ‘fat-free’, which can help manage calorie intake, but that doesn’t necessarily mean they are healthier options overall.

Bottom Line

It’s important to understand the role fats play in our diets and aim to make healthy food choices but striving for a healthy diet should include true acceptance of the concept of balance.

Taking pleasure in what you eat is important, and you should not have to constantly restrict foods you like. It’s okay to eat and enjoy an ice cream or higher-fat yogurt or chocolate.

Food diversity is important for health and enjoying those diverse and delicious meals with friends and family – establishing those human connections – is vital to our emotional and physical wellbeing.

Having a healthy diet means being flexible in our choices and at the same time also being mindful of what we’re eating, what the ingredients are and what the source is. The idea is to maintain a healthy relationship with food, while ensuring a good overall diet quality by having a variety of nutritious and enjoyable foods.

This article is made possible by support from Danone Canada and Oikos Canada