Dietary fats, oils and cholesterol

Dietary fats, oils and cholesterol

You need a small amount of fat in your diet for healthy functioning. Oils and fats supply calories and essential fats and help your body absorb fat-soluble vitamins such as A, D, E and K. The type of fat consumed is as important for health as the total amount consumed.

That's why it's important to choose healthier unsaturated fats. Eating too much and the wrong kinds of fats, such as saturated and trans fats, may raise unhealthy LDL cholesterol and lower healthy HDL cholesterol. This imbalance can increase your risk of high blood pressure, narrowing of the arteries (atherosclerosis), heart attack and stroke.

Canada's Food Guide recommends that you include a small amount  – 30 to 45 mL (2 to 3 tablespoons) – of unsaturated fat each day (also known as mono- and polyunsaturated fat). Make sure the oil you use in cooking, salad dressings, soft non-hydrogenated margarine and mayonnaise contain mono- and polyunsaturated fats such as olive, soybean, canola or peanut oils.

Monounsaturated fats

These have been shown to improve blood cholesterol levels. They're found in olive oil, canola oil, peanut oil, non-hydrogenated margarine, avocados and some nuts such as almonds, pistachios, cashews, pecans and hazelnuts.

Polyunsaturated fats

These fats can lower bad cholesterol levels (LDL cholesterol). One type of polyunsaturated fat is omega-3, which can help prevent clotting of blood, reducing the risk of stroke and also helps lower triglycerides, a type of blood fat linked to heart disease. The best sources of omega-3 fat are cold-water fish such as mackerel, sardines, herring, rainbow trout and salmon, as well as canola and soybean oils, omega-3 eggs, flaxseed, walnuts, pecans and pine nuts.

Another type of polyunsaturated fat is omega-6. It helps lower LDL cholesterol, but in large amounts it's thought to also lower the good HDL cholesterol. Eat it in moderation. Omega-6 is found in safflower, sunflower and corn oils, non-hydrogenated margarine and nuts such as almonds, pecans, brazil nuts and sunflower seeds. It is also in many prepared meals.

Saturated fat

Foods high in saturated fat include fatty meats, full-fat dairy products, butter, hard margarines, lard, coconut oil, ghee (clarified butter), vegetable ghee, and palm oil. Saturated fat can raise unhealthy LDL cholesterol.

Trans fat

Like saturated fat, trans fat raises unhealthy LDL cholesterol but also lowers healthy HDL cholesterol. Try to limit products that list vegetable oil shortening or partially hydrogenated oil in the ingredients. Trans fat is found in partially hydrogenated margarines, deep-fried foods from fast-food outlets (fries, doughnuts), and many packaged crackers, cookies and commercially baked products.

How much fat should you eat in a day?

Remember that since all fats are calorie-heavy, you'll need to use even the healthier ones in moderation. A healthy eating pattern includes between 20% to 35% of your day's calories from fat. For women, this works out to 45 to 75 grams of fat a day, and for men, 60 to 105 grams of fat a day. (For example, 15 mL (1 tbsp) of oil equals about 14 grams.)

The amount of fat a child or adolescent needs depends on their height, build, gender and activity level. Young children need a slightly higher amount of fat for growth and development, but this need decreases as they age.

What is dietary cholesterol?

The liver makes about 80% of the cholesterol in your body. The other 20% comes from the foods you eat. The foods that raise your blood cholesterol the most are saturated fat and trans fat in such foods as fatty meat and whole-fat dairy products, snack foods and some ready-prepared foods. Foods that have high levels of dietary cholesterol include egg yolks, organ meats, shrimp, squid and fatty meats.

Dietary cholesterol only has an effect in some people. From a nutrition perspective, the best way to control blood cholesterol is to eat a healthy diet that is lower in fat, especially saturated and trans fat. Studies show that for healthy people with no history of heart disease, diabetes or high blood cholesterol, eating an average of one egg per day (or seven eggs per week) does not increase the long-term risk of heart disease.

The recommended daily intake (RDI) of dietary cholesterol for most healthy individuals is 300 mg of dietary cholesterol per day with less than 7% of calories from saturated fat.

People with heart disease or diabetes are advised to limit themselves to 200 mg of dietary cholesterol per day with less than 7% of calories from saturated fat. Do that by cutting down on foods that are high in cholesterol, saturated fat and trans fat.

Last reviewed August 2012

Last modified August 2012