Fats have gotten an unnecessary bad rep in the past few decades. No matter what the latest diet trend is, it’s guaranteed that there’s a polarizing opinion on whether fat is the devil (like in the low fat craze of the 70s and 80s) or completely celebrated and encouraged (like right now in the insanely popular ketogenic diet trend). So what’s the truth?
Stating that one macronutrient is “good” or “bad” for you without looking at the big picture is disregarding the complicated functions of our bodies. Fat is an essential macronutrient. This means that consuming it is absolutely necessary for our bodies to work properly. Fat is necessary for our cells to function properly and perform cell signalling within our bodies. It’s also essential for storing micronutrients such as Vitamin A, D, E and K. However, this doesn’t mean that all fats are created equal.
Saturated fats are generally those that are solid at room temperature. They are typically found in animal products (dairy, meat, eggs and butter), but are also found in coconut oil and palm oil. Saturated fat has been traditionally linked to increased blood cholesterol and increased insulin resistance, which could lead to an increased risk of cardiovascular disease and diabetes. However, there has been considerable controversy recently over the harmful effects of consuming saturated fat. Many of the studies stating that saturated fat do not have harmful effects have methodological flaws, confusing the results even more.
What’s clear from studies is that what you are replacing saturated fat with in your diet matters. Replacing foods high in saturated fat, such as animal products, with refined starches and sugary foods will likely have no beneficial effect on your health. However, replacing foods high in saturated fat with those that have been proven to have beneficial effects to our health such as vegetables, fruit, legumes, whole grains, nuts and seeds will likely have a beneficial effect. For example, replacing saturated and trans fatty acids with unsaturated fats has shown to have beneficial effects on insulin sensitivity and is likely to reduce risk of type 2 diabetes. Due to the controversy surrounding saturated fat, I would recommend to err on the side of caution and consume foods high in saturated fat in moderation.
Fats rich in monounsaturated fats are generally liquid at room temperature but thicken and get cloudy when refrigerated, such as olive oil. Monounsaturated fats may have beneficial effects on health, modestly decreasing blood cholesterol levels.
Replacing saturated fats, trans fat or refined carbohydrates with monounsaturated fat reduces total LDL “bad” cholesterol. Monounsaturated fatty acids can be found in olives, olive oil, avocados, and most nuts.
Polyunsaturated fats include both omega-3’s and omega-6’s. Oils that contain mostly polyunsaturated fat at liquid at both room temperature and when refrigerated.
Replacing saturated fats in the diet with polyunsaturated fats has been shown to reduce LDL cholesterol, and reduce the risk of cardiovascular disease. High quality plant-based sources of polyunsaturated fats are vegetable oils, seeds, nuts, grains and legumes.
*I will be doing a blog post exclusively on polyunsaturated fats (omega 3 and 6) and essential fatty acids (linoleic acid and alpha-linoleic acid) so stay tuned!
Approximately 90% of trans fats are produced by hydrogenation. Hydrogenation adds a hydrogen atom to an oil that that is polyunsaturated (such as vegetable oil) to make it a semi-solid at room temperature (such as margarine). The other 10% of trans fats are formed in the stomach of ruminant animals. Trans fats are often added to processed food to increase the shelf-stability of the product, making it last longer without going bad. It also increased the temperature needed for the fat to melt.
Trans fats are mostly found in deep fried foods, ready-to-eat frozen foods, stick margarine, commercially baked goods, convenience fast foods, packaged sweet snacks, snack puddings, and packaged salty snacks. Trans fat can also be found in small amounts naturally in animal foods. This type of naturally occurring trans fat needs further studying to determine if it has similar effects of manufactured trans fat.
Trans fat is strongly associated with and increased risk of cardiovascular disease and all-cause mortality. Trans fats are not beneficial for our health, and should be consumed in as limited quantities as possible.
There’s no way I could do a post about oil without mentioning coconut oil. Coconut oil is high in saturated fat. Because of this, it should be used in moderation, as other foods high in saturated fat should be as well.
When following a whole-foods, plant-based diet saturated fat intake is minimized due to lack of animal products. This leaves room for the addition of a moderate amount of coconut oil, as saturated fat may not be harmful in low quantities. This means it could be added to the occasional dessert or recipe, but shouldn’t be seen as a “health food” as there are no conclusive scientific studies touting its benefits.
Smoke point of Oils
Some oils have a higher smoke point than others, meaning they are more suitable for cooking at high temperatures. Try to use high smoke point oils if using oil during cooking, and save low smoke point oils for drizzling on salad, or making homemade spreads or dips.
High smoke point oils:
- avocado oil
- safflower oil
- Sunflower oil
- Extra light olive oil
- Peanut oil
- Coconut oil
- Grapeseed oil
Low smoke point oils (best used not cooked):
- Flaxseed oil
- Extra virgin olive oil
- Hemp oil
- Sesame oil
As mentioned above, fats are necessary for healthy body functioning. However, as we’re mentioned some fats are more beneficial than others. The World Health Organization recommends that we consume 15-30% of our calories from fat. When including a variety of plant-based foods into our diets that focus on unsaturated fats, we can be at the higher end of this spectrum with minimal health concerns.
Adding oils when cooking or to add as a topping to foods is perfectly fine in moderation. However, it’s important to consider that one gram of fat contains 9 kilocalories (carbohydrates and proteins contain 4 kilocalories per gram). This means that 1 tablespoon of oil contains approximately 120 calories, which can add up quickly for a part of the meal you might not even really notice. This doesn’t mean that you shouldn’t include oils in your diet, as they can be a valuable part of cooking or baking. It’s simply important to remember that moderation is important.
My philosophy is to always try to get nutrients from the whole food source rather than isolates (oils). I recommend including whole, plant-based foods in your diet that have naturally occurring unsaturated fats as your primary fat source. This includes foods such as avocados, olives, coconut, nuts and seeds (and nut and seed butters). These foods also have other beneficial ingredients such as fibre, protein, carbohydrates, and micronutrients.
Takeaway message: Fats are a necessary part to the human diet. Try to stick to whole food, plant-based sources of fat most of the time. These include avocados, olives, nuts, seeds (and their butters) and coconut.
To learn about protein, check out my blogpost here.
*Children require more fat than adults. Please speak to your dietitian for personalized recommendations for yourself or your child.