The total amount of fat you eat, whether high or low, isn’t really linked with disease. What really matters is the type of fat you eat. The “bad” fats—saturated and trans fats—increase the risk of heart disease, high blood pressure, colon cancer and obesity. The “good” fats: mono-unsaturated and poly-unsaturated fats: lower disease risk. The key to a healthy diet is to substitute good fats for bad fats—and to avoid trans fats.
Good fats are needed by the body for many essential functions such as absorbing vitamins A, D, E and K. Fats provide essential fatty acids that our bodies can’t manufacture, help to control body temperature and provide padding for the organs. They also supply energy and are digested slowly helping us to feel full longer.
What is the difference: saturated vs unsaturated
Fats that are saturated tend to be more solid at room temperature and can be found in milk, cream, butter, hard cheese, meats and palm oil. Animal fats derived from ruminants (sheep and cattle) are largely saturated. Fats from other animals (eg. pork and chicken) are less saturated and contain some poly-unsaturated fats. Game meats (eg. kangaroo) are lower still in saturated fat. Fats from fish are generally highly unsaturated and contain the poly-unsaturated fatty acid known as omega-3.
Fats that are unsaturated tend to be liquid at room temperature, such as those found in vegetable oil. Unsaturated fats consist of mono-unsaturated fats and poly-unsaturated fats. Mono-unsaturated fats are found in high amounts in natural foods like nuts, avocados, olive oil, peanut and sesame seed oils, grape-seed oil and canola oil. Poly-unsaturated fats can be found in foods such as oily fish (sardines and tuna), soyabean, seeds, sunflower oil and walnuts.
Omega-3 fats- one of the good guys
Omega-3 fats are a type of poly-unsaturated fat and are essential nutrients required for every cell in the body. They are particularly important for a healthy heart, healthy eyes, and good brain function. There are two types of omega-3 fats – plant and animal. Plant type omega-3 fats are found in linseeds, canola oil, walnuts, wheatgerm and green leafy vegetables. Animal type omega-3 fats are found mainly in fish and seafood, but there is also a little in meat.
Coconut Oil – a unique good fat
Coconut oil is solid at room temperature and for many years has been regarded as a bad fat. But due to its unique cell structure of medium-chain triglycerides or MCT’s, it is actually very good for us. Coconut oil is the richest source of MCT’s found in nature. MCT’s easily go through cell membranes and are quickly and effectively broken down and utilised by the body – not stored as fat. MCT’s are used to produce energy similar to carbohydrates and are not circulated in the bloodstream like other fats. For this reason, they do not contribute to weight gain.
So when you use coconut oil in food, you can eat the same types of foods as you normally do, yet consume fewer calories. Studies have shown when oils containing MCT’s are used in place of fats in the diet, people can lose as much as 16kg a year, even when total calorie consumption remains the same! (St.Onge, M.P and Jones, 2002, Physiological Effects of medium-chain triglycerides: potential agents in the prevention of obesity. Journal of Nutrition 132(3):329-332).
Trans fats – the worst kind of fat
Many of us have picked up foods in the supermarket with ingredients written in code such as “partially hydrogenated vegetable oil”, “hydrogenated oils” and “vegetable shortening”.
This code refers to trans fats – a type of unsaturated fat formed by the hydrogenation of vegetable oils during the manufacturing of some foods such as cakes, biscuits and other processed foods but are also found naturally in smaller amounts in ruminant animal foods. Trans fats are also found in some brands of margarine.
Trans fats are mostly mono-unsaturated, but their molecules have a different shape from the naturally occurring mono-unsaturated fats that are abundant in canola, olive and peanut oil. Your body sees a molecule of trans fat as a saturated fat and treats it the same way. The consumption of trans fats increases one’s risk of coronary heart disease by raising levels of “bad” LDL cholesterol and lowering levels of “good” HDL cholesterol. Health authorities worldwide recommend that consumption of trans fat be reduced to trace amounts. Denmark is the first country in the world to have banned the use of hydrogenated fat. Since the beginning of last year it’s been illegal to sell products in which trans fat is more than 2% of the total fat.
Labelling of food
At present, the Australia New Zealand Food Standards Code does not require manufacturers to label the trans fatty acid content of foods unless they make a nutrition claim about cholesterol, saturated, unsaturated or trans fatty acids. However, voluntary labelling is permitted and many edible oil spread manufacturers in Australia and New Zealand have chosen to voluntarily label their products.
Final note: just because a food has been prepared without partially hydrogenated oil doesn’t necessarily make it healthy, cautions Walter Willett, chair of the Department of Nutrition at the Harvard School of Public Health. “It can be trans-free and still contain a lot of sugar, easily digestible (low fiber) carbohydrate and starch, or saturated fat, which isn’t a good choice.”
Percentages of poly-unsaturated (P), mono-unsaturated (M) & saturated (S) fatty acids in common margarines, cooking oils and fats (in the order P:M:S):
Canola oil 30:63:7
Safflower oil 77:14:9
Sunflower oil 66:23:11
Olive oil 10:76:14
Soybean oil 62:23:15
Peanut oil 36:45:19
Cottonseed oil 58:16:26
Palm oil 30:39:51
Mono-unsaturated margarine 22:63:15
Poly-unsaturated margarine 41:40:19
Table margarine 33:33:34
Butter 7:36:57
Many poly-unsaturated fats have demonstrated cholesterol-lowering properties, and are rich in omega-6 fatty acids. The typical modern diet is high in the omega-6 fatty acids to the tune of 14 to 25 times more than omega 3 fatty acids. While both of these fats are essential to our bodies, each has unique virtues. Fish oils contain two omega-3 fatty acids known as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). On the other hand, the popular omega-6 fat, Flaxseed oil is rich in alpha-linolenic acid, the “parent” fatty acid to DHA and EPA. Our bodies convert alpha-linolenic acid into EPA and DHA. However, other foods in our diet can easily put the brakes on this conversion process. For instance, a diet that’s rich in trans-fatty acids, such as hydrogenated oils; like those found in some margarines, chips, cakes and cookies, will ‘interfere’ with your body being able to enjoy the health giving benefits of EPA and DHA.
It’s clear that no two fats are alike. Essential fatty acids (both mono & poly-unsaturated) are a useful addition in the diet to anyone who wants a leaner, healthier body. They can be consumed by incorporating plentiful quantities of fresh nuts, seeds and high-fat, cold water fish (such as tuna and salmon) in your meals. If this isn’t possible, take fish-oil or flax-seed oil supplements, and limit saturated and trans fats wherever possible.
8 Quick Tips for ensuring healthy fats are included in your diet:
- High heat, light and oxygen destroy EFA’s, so when consuming good fats for their EFA content, avoid cooked or heated forms. For example raw nuts are a better source than roasted nuts. Never re-use any type of oil, and don’t use flaxseed oil for cooking. Extra virgin oil and grape-seed oil can withstand high heat well, so are best used for stir-frying, etc
- Ditch the trans fat. In the supermarket, read the label to find foods that are trans free. In restaurants, steer clear of fried foods, biscuits, and other baked goods, unless you know that the restaurant has eliminated trans fat.
- Replace hydrogenated fats (some margarine brands), cholesterol-based fats (like butter) with healthy EFA (liquid plant oils) for cooking and baking. For example use extra virgin olive oil on roasted vegetables instead of butter, and add a little sea salt (to give you the same salty taste of margarine). If using a spread make sure it’s free of partially hydrogenated oils and trans fat.
- Eat at least one good source of omega-3 fats each day. Fatty fish, walnuts, and canola oil all provide omega-3 fatty acids.
- Sprinkle flaxseed meal on cereals and casseroles etc for an easily digested source of fats, fibre and protein.
- Replace shortening in recipes with half as much virgin olive oil or coconut oil.
- Replace oily snacks like potato chips with fresh nuts and seeds.
- Think Mediterranean! Go lean on meat and milk. A diet rich in mono-unsaturated fats, fruits, vegetables, whole grains and seafood will keep you trim and healthy.
Fat is an essential part of the diet and needs to be eaten every day. It is an important factor in normal growth and development and the maintenance of good health. There is no doubt that we do need some fat in the diet everyday – but remember, it’s not only the total amount of fat you eat that matters, but the type of fat. By choosing fats wisely, you’ll be taking a big step in keeping yourself healthy for life!
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