Fat has had its fair share of debates in dietary circles – the low-fat movement from the 1980s told us we should cut out fat, while high-fat diets like keto tell us the opposite.
How do you know where the answers lie? The reality is that fat is built into the American diet. It’s in the oil we use in the pan, the fish we cook, the fruits and vegetables we eat (think avocado). It’s also an essential part of a healthy diet, crucial for energy, cell function, hormone production and nutrient absorption.
Which are the healthiest fats?
Not all fats are created equal, says registered dietitian Chris Mohr, but overall fat is essential in our diets. According to Mohr, the “healthiest” fat is the one we need but often don’t get enough of – omega-3s.
Omega-3s are polyunsaturated fats that are essential nutrients, meaning our bodies can’t make them. But according to a study based on the National Health and Nutrition Examination Survey, 68% of adults and over 95% of children consume less than the recommended amount.
Omega-3s are most commonly found in fish, but you can also get them from dark leafy vegetables, linseeds, hempseeds and walnuts. Omega-6s, another type of polyunsaturated fat, are also essential, but Mohr says we don’t have to worry about getting them in our diet because they’re found in many cooking oils, nut butters and eggs.
Ideally, says Mohr, you’ll get a balance of fat sources. According to the Dietary Guidelines for Americans, fat should make up 20-35% of our daily calorie intake, with less than 10% of that coming from saturated fat. The guidelines also say to avoid trans fats, which are known to increase the risk of heart disease, stroke and type 2 diabetes.
“Too much of some types of fat may not be best for us, while others are fantastic,” says Mohr. “There’s some nuance in terms of not just the quantity, but also the quality of the fat we’re eating.”
There are four main types of fat – trans fat, saturated fat and two types of unsaturated fat:
Trans fats: Usually found in the form of partially hydrogenated oils, this is known to increase the risk of heart disease, stroke and type 2 diabetes.
Saturated fat: Most commonly found in solid forms such as meat, butter and coconut oil.
Monounsaturated fat: A heart-healthier option that raises ‘good’ cholesterol levels.
Polyunsaturated fat: Contains beneficial omega-3 and omega-6 fatty acids
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What are the benefits of omega-3s?
Omega-3 fatty acids support heart health and may also help reduce the risk of cancer, cognitive disorders and eye disease. According to Mohr, a lack of omega-3s can manifest itself in dry skin and brittle hair. Studies have also shown a link to mood – omega-3s have anti-inflammatory properties that may relieve depression.
The Dietary Guidelines for Americans recommend at least 8 ounces of seafood per week for adults on a 2,000-calorie diet. If you are pregnant or breastfeeding, it is recommended that you consume between 8 and 12 ounces of low-mercury fish per week to provide developmental benefits for your baby. One serving is about 4 ounces of fish.
Fish is the most common source of omega-3s – salmon and tuna are old favourites, but Mohr recommends trying herring, sardines and anchovies. You can also get some from leafy greens, vegetable oils, nuts, flaxseed and linseed oil.
For those who don’t eat enough fish, Mohr suggests looking into omega-3 supplements that contain at least 500 milligrams. If you don’t eat fish, try an algae oil supplement, which is where the fish get their omega-3s from.
Is saturated fat bad?
Much of the public knowledge about saturated fat is that it raises low-density lipoprotein cholesterol (“bad cholesterol”) and the likelihood of heart disease. But some recent studies challenge current guidelines and suggest that the link between saturated fat and increased risk of cardiovascular disease is less strong than previously thought.
According to Mohr, saturated fat is “one piece of the puzzle” when it comes to cardiovascular disease risk. When people are told to reduce saturated fat in their diets, they often increase their intake of refined carbohydrates such as added sugars instead, Mohr says. This may lower LDL, says Mohr, but it also lowers high-density lipoprotein cholesterol (“good” cholesterol) and raises triglycerides. It may be healthier to replace saturated fats with unsaturated fats in the diet, rather than just focusing on reducing saturated fats.
The takeaway then, he says, is to focus most of your fat intake on monounsaturated and polyunsaturated and replace saturated fat intake with unsaturated fats when you can.
“Fats are essential, we just need to be wary of what we’re eating, how much we’re eating,” Mohr says.
