Fat has been at the centre of much debate over the last century because of the high stakes involved. Fat has long been vilified as the enemy to heart health and is only now making its comeback. Research is emerging that suggests that fat may not be the culprit after all, but unfortunately the recommendations have still not caught up with the data. Through all the contradictory information presented to the public, it’s no wonder that we still maintain beliefs that may not have any real evidence to back them up! On the contrary, we also continue to preach ideas about fat that have long been discredited.
My quest to simplify fats has quickly turned into a dissertation. However, I hope that I can provide a concise overview that will ultimately help you make the best decisions in the kitchen.
What is fat? Fat is a macronutrient that provides us with a condensed form of energy. We need to consume fats in order to provide our bodies with nutrients that we can’t make ourselves, as well as help us build hormones and absorb certain vitamins.
What kinds of fat are there?
Trans Fats – Created as a means to extend the shelf life of food products. These fats have no nutritional benefits and are known to be harmful to heart health. Look out for ingredients such as “hydrogenated” or “partially hydrogenated” to indicate that trans fats are hiding in your food products. Yes, this means that you have to read the ingredients list! As a general rule, trans fats are found in hard margarines, vegetable shortening, deep fried foods such as fries and doughnuts, and many packaged crackers, cookies, and commercially baked products.
Saturated Fats – These are naturally occurring fats usually found in animal meats, eggs, and dairy products, as well as in plant-based oils like coconut and palm. They are also found in most highly processed and packaged foods. These fats have been given a bad reputation over the decades as they were thought to be the cause of heart disease. However emerging evidence suggests that their health effects may vary depending on their dietary source. This means that we should still be avoiding those packaged processed foods such as deli meats, cookies, and chips, but that the naturally occurring saturated fats may not be so bad after all.
Unsaturated Fats – This category includes monounsaturated fats and polyunsaturated fats. Monounsaturated fats are found in some vegetable oils, avocados, and certain nuts. There is no dispute about the fact that they improve heart health. Polyunsaturated fats include the well-known omega-6 and omega-3 fatty acids. Omega-6 fatty acids are pro-inflammatory nutrients that are found in safflower, sunflower, soybean and corn oils. Omega-3 fatty acids are anti-inflammatory nutrients that are found in cold-water fish (particularly salmon, trout, and sardines), as well as oils made from canola, flaxseed, walnut, hemp, and avocado. I wouldn’t get too caught up in the details about how these fatty acids work in the body. All we need to understand is that they are essential to life and that the ratio between consumed omega-6 and omega-3 is essential because they play contradictory roles in the body. It is estimated that in North America we consume on average a ratio of 10 omega-6 to 1 omega-3, where as the recommendation is closer to 4:1. This unbalance is leading to chronic diseases such as cardiovascular disease, inflammatory diseases, and certain types of cancer.
Dietary Cholesterol – Your body produces about 80% of the cholesterol in your body and the rest comes from dietary sources. Although there are high levels of cholesterol in certain foods such as eggs, liver, and shrimp, it is the saturated and trans fats that have the biggest impact on blood cholesterol levels. That means you can have your egg yolks again at breakfast!
What are the current Canadian Guidelines? Shockingly, our guidelines are based on data from 70 years ago! The guidelines suggest limiting saturated fat by restricting meats, butter, high fat dairy products, and replacing them with monounsaturated and polyunsaturated fatty acids. The take-home message has always been: buy low fat/no fat food products, replace butter with margarine, and limit meat eating to skinless chicken breast. Besides the fact that this is a bland and boring diet to adhere to, we also have evidence that proves that these recommendations are way out of date.
So how do we choose which fats to use? For this answer, we have to understand the properties of different fat sources. A smoke point is the temperature at which oil will break down into its smaller components, and where you literally see smoke. If the oil continues to be heated, it can produce chemicals that are linked to causing cancer. For this reason we want to pick the best fat for which food we are preparing.
1. Butter and margarine were not mentioned on the smoke point list above. They both have a medium smoke point. Butter is high in saturated fats and is one of the most natural fats available if it is organic and grass-fed. Conversely, margarine is high in unsaturated fats, but can contain trans fats.
2. Be cautious about choosing oils that are highly processed, particularly canola oil, corn oil, and soybean oil.
3. Pick two or three oils maximum to use as staples in your kitchen. Store them in a cool dark place (or refrigerate as indicated), as time and heat can impact the taste and quality of your oils over time.
4. Oils that are used for frying that are subsequently strained and reused will lose their integrity.
It is easy to see why fats were bullied for so long by researchers and the public. This is complex stuff! When it comes down to it we want to choose fats that best suit what we are cooking. Ideally we move away from packaged and heavily processed foods, including processed oils, and move towards whole or homemade foods. Like anything, we have to look at fats in the bigger context as food as a whole and enjoy them in moderation and variety along with the other foods in our diet.
P.S. For all those unanswered questions about fat, please connect with me by e-mail or feel free to comment below.