Despite what you might think, fat is not all bad, or rather, not all fat is bad – in fact, some fats are even crucial to good health. However, that doesn’t give us the go-ahead to load up on fries; research continues to show that a diet high in certain fats is an unquestionable and primary cause of heart disease.
Read on to find out all about fat and how to incorporate it into a healthy diet.
What is fat?
Fat is an oily, greasy material found in animals (including humans) and plants. Much as we might prefer to have less of it, fat is a fact of all life. Almost nothing lives without it.
There are different types of fat including saturated, monounsaturated, polyunsaturated, and trans. Foods almost always contain more than one of these fats, but some foods have more “bad” fat than others. If you really want to be fat-savvy, you need to know what’s what.
- Saturated fat is “bad” fat. Too much of it increases your cholesterol levels, raises the risk of blood clots, atherosclerosis (artery blockage), and coronary heart disease. Saturated fats are found mainly in animal products such as full cream milk, cheese, butter, cream, fatty meats and sausages, and also in processed foods. Coconut, palm and other tropical oils are the only plant foods that contain significant amounts of saturated fat. Saturated fats are usually solid or waxy at room temperature.
- Trans fat is “the other bad fat”. This fat also raises blood cholesterol levels and increases the risk of heart disease. It is made by adding hydrogen to vegetable fats – a process called hydrogenation. Trans fats are found mostly in baked goods and fried foods, and in shortenings and margarines that are “hydrogenated” or “partially hydrogenated.”
- Polyunsaturated fats are “good” fats and come in two forms: omega-6 and omega-3. Omega-6 polyunsaturated fats tend to lower blood-cholesterol. Rich sources include safflower, sunflower, and corn oils. Omega-3 polyunsaturated fats can also lower blood-cholesterol when used in place of saturated fats. Omega-3 fats have many other health benefits, such as lowering blood-triglycerides and blood-pressure levels as well as reducing the risk of heart disease. They may also protect against some cancers. Sources of omega-3 fats include canola, flaxseed, walnut, and soybean oils, and oily fishes like mackerel, herring, tuna, and salmon. (Note: Sources of omega-6 – safflower, sunflower, and corn oils – are overabundant in the typical diet. Aim for a 1:1 ratio of omega-6 to omega-3 fats in your diet).
- Monounsaturated fats are also “good” fats as they tend to lower “bad” LDL-cholesterol and maintain the protective “good” HDL-cholesterol in the bloodstream – but only if they replace saturated fats in the diet. Foods rich in monounsaturated fat include olive and canola oils, peanuts, and avocados.
- Cholesterol is not a fat per se; it is more like a cousin of fat. Both fats and cholesterol belong to the lipid family. Cholesterol fulfils many important functions in the body. For example, it is used in the making of hormones, vitamin D, and bile acids which help in the digestion of fat, as well as in the maintaining of cell walls. The problem is that your liver already makes around 1000mg of cholesterol per day, which is almost as much, if not all, of the cholesterol your body needs to maintain these vital functions. So, when you consume too much dietary cholesterol as well (mainly from foods high in saturated fat), your body cannot get rid of the excess. The fats build up in various cells and tissues of the body, leading to heart complications and other health problems. Cholesterol is found in high-fat dairy products, egg yolks, high-fat meat, and poultry skins.
What is fat for?
Skinny people don’t always invoke jealousy. In societies where food is scarce, body fat is a sign of wealth, and overweight people are envied because their bodies show that they have enough to eat. In Australia today, of course, it’s those of us who get too much fat whose lives are in danger. But that doesn’t change the fact that some fat is necessary to stay alive.
Fat has many important roles in the body. For example, fat provides a highly-concentrated form of energy. One gram of fat gives you nine calories of energy, which is more than twice that provided by carbohydrates and protein.
Fat also enables your body to transport, store and absorb the fat-soluble vitamins A, D, E, and K. An absence of fat may mean a deficiency in these vitamins. Fat-soluble vitamins help to regulate blood pressure, heart rate, blood vessel constriction, blood clotting, and the nervous system.
Fat also provides insulation and a protective cover for vital organs. In an average adult, as much as 4 kgs of fat is found around the liver, heart, kidneys and other organs.
Essential fatty acids from omega-3 fats cannot be made by your body, and therefore must be supplied through your diet. Dull, lifeless hair and dry skin can be a sign that you may not be getting enough of these fats.
And of course, fat adds extra flavour, aroma, and texture to food, which is perhaps why we so often and too easily eat too much of it.
How much is too much?
The right amount of fat keeps you alive; a high-fat diet, however, can increase the risk of heart disease and certain cancers.
Most Australians consume over 40 percent of their daily calories from fat, which is far from the 20-30 percent they should be aiming for. This overload of fat leads to obesity and heart disease, as well as high blood-cholesterol and countless other health problems. The recommended 20-30 percent of daily calorie intake from fat equates to about 30-60 grams for children and women, and 40-80 grams for teenagers and men, depending on activity levels. (Infants and children under three should not have fat intake restricted).
As well, less than 10 percent of total calories should come from saturated fats and/or trans fats. Cholesterol intake should be less than 300 mg a day. If you have high blood-cholesterol levels, you should aim for less than 200 mg a day.
|Desirable Daily Fat Intake (based on 20-30% fat from total calories)|
|Daily total calories||Calories from fat|
|Daily total fat grams (20-30% cals)||Daily saturated fat grams (10% of cals)|
|1200 cals||240-360 cals||27-40g||13g|
|1500 cals||300-450 cals||33-50g||17g|
|1800 cals||360-540 cals||40-60g||20g|
|2000 cals||400-600 cals||44-67g||22g|
|2200 cals||440-660 cals||49-73g||25g|
|2500 cals||500-750 cals||56-83g||28g|
|2800 cals||560-840 cals||62-93g||31g|
|3000 cals||600-900 cals||67-100g||33g|
|3500 cals||700-1050 cals||78-117g||39g|
|4000 cals||800-1200 cals||89-133g||45g|
Note: At lower calorie levels, the percent of fat calories should decrease to allow for protein calories (which have nutritional priority).
Figuring fat into your diet
It’s all very well to understand the dos and don’ts of fat consumption, but when it comes to actually implementing good “fat” practices in your diet, the numbers and percentages and grams can get kind of confusing. But it doesn’t have to be difficult – just follow these steps:
- The first rule is “moderate, don’t eliminate.” Some fat is essential to your diet, so don’t cut it out completely.
- Work out exactly how much fat you should be getting by using the table above. For example, if your daily calorie intake is 1800 calories, 360-540 of those calories (20-30 percent) should be from fat. This equates to 40-60 grams of fat.
- Before you eat something, read the nutritional label, or consult your Pocket Calorie, Fat and Carbohydrate Counter to see how many grams of fat are in that food. Deduct those grams from your recommended daily intake. For example, if you are on 1800 calories a day and you eat a tub of strawberry yoghurt (6g fat) then you can eat another 34-54 grams of fat during the rest of the day.
- One food can contain a variety of fats, so watching your fat intake means being aware of both the amount and the types of fat in what you eat. Get to know which foods have which fats, and make an effort to include more sources of omega-3 and less sources of saturated fat in your diet. Although trans fats may not yet be listed on all food labels, be aware that they are contained in most baked goods and fried foods.
- Don’t forget to account for portion size when counting calories and fat grams!
Remember that 20-30 percent of calories from fat doesn’t equate to 20-30 percent in each individual food that you eat, but rather to your overall diet. Our normal diet is made up of foods that are either well above or below 30 percent.
Also remember that food doesn’t have to look or taste greasy to contain a lot of fat. It can be difficult to detect fat in some foods because the taste of fat is often hidden by other flavours and textures. For example, ice cream, mayonnaise, cheese, muesli bars, chocolate, and cake all have a high fat content, but the taste and feel of that fat is not as detectable as in a greasy burger or chips. Thus, a large amount of fat from these foods can be unwittingly consumed – and with it, excessive calories.