Nutritionist Fiona Carruthers and HFG dietitian Zoe Wilson provide answers to some of your most common questions about the ‘F’ word.
The prevailing wisdom used to be that all fat was bad for you – but it’s no longer that black and white. In the last decade or so, the issue has evolved into a discussion about ‘good’ vs ‘bad’ fat – and what constituted each type of fat. Yet it‘s not as simple as cutting all ‘bad‘ fat completely out of your diet since most foods contain both healthy and unhealthy fats.
We sift through the confusing (and sometimes conflicting) messages about fat and show you which foods to choose... and which ones to avoid.
‘Good’ and ‘bad’ fats – what’s the difference?
There are three major types of fat – saturated, monounsaturated and polyunsaturated fats. Every food containing fat generally has a mixture of saturated, mono- and polyunsaturated fats, but is classified by the most predominant type of fat they contain. For example, olive oil is classified as a monounsaturated fat, but it also contains a small amount of saturated fat. The ‘Types of fat and where you‘ll find them‘ (see below) provides a list of foods classified by their predominant fat type. Remember, even if you are following a low-fat diet, it‘s important to include some mono- and polyunsaturated ‘good‘ fats as they contain certain vitamins and essential fatty acids (but do reduce your saturated fats!).
What are the different types of fats?
Monounsaturated: Often referred to as one of the ‘good’ or ‘heart-healthy’ fats, they lower total and ‘bad’ (LDL) cholesterol and also raise ‘good’ (HDL) cholesterol.
Polyunsaturated: Another of the ‘good’ fats, including omega-3 and omega-6 fats, they have many health benefits, including reducing total and LDL cholesterol. Omega-3 fats can also help reduce inflammation, are vital for cognitive function and can improve the flexibility of artery tissue, which may help lower your blood pressure.
Saturated: Often referred to as ‘bad’ fats, they can increase total and LDL cholesterol, and thus increase the risk of heart disease.
Trans fat: Another of the ‘bad‘ fats, these unsaturated fats have been chemically altered to act as a saturated fat and increase LDL cholesterol. They also reduce our HDL cholesterol levels, increasing the risk of heart disease.
Dietary cholesterol: Previously thought to be the ultimate ‘baddy’ in the fat world, it has since been discovered that while dietary cholesterol may increase your total and LDL cholesterol, it has much less of an effect on cholesterol levels than saturated or trans fats.
Types of fat and where you’ll find them
Canola oil and canola-based margarine Olives, olive oil and olive-based margarine Peanuts, peanut oil and peanut butter Avocados Almonds Cashews Macadamia nuts Pecans Pistachios
Butter or reduced-fat table spread – which is better for me?
Are you shying away from reduced-fat table spreads because you are concerned about the amount of added chemicals and preservatives? While it’s understandable to assume that butter – made purely from cream and salt – is the healthier spread, since it contains only natural ingredients, this isn’t necessarily the case as it's high in saturated fat. While reduced-fat table spreads are manufactured products, they are based on healthy oils such as canola, sunflower and safflower – which contain ‘good’ mono- and polyunsaturated fats. Some reduced-fat spreads are also fortified with beneficial nutrients like vitamins or plant sterols.
Also, keep in mind that all ingredients added to food in Australia undergo rigorous testing and are regularly reviewed by Food Standards Australia and New Zealand (FSANZ). There is no evidence that margarines or spreads are harmful. In fact, research shows that some may positively affect your health, for example by reducing cholesterol levels.
You may have also heard that reduced-fat table spreads contain trans fats. In the early days, some of the unsaturated oils in margarine and reduced-fat table spreads were converted to trans fats to increase their shelf life. However, the vast majority of reduced-fat table spreads in Australia now have very little or no trans fat (less than 1% of total fat). These days, trans fats are more of a worry in foods like chips, cakes and packaged snacks.
I've heard full-fat dairy is actually better for me – is this true?
While most Australians currently have too much saturated fat in their diets, some research shows that not all foods containing saturated fat should be condemned, as other nutrients within those foods could be beneficial to heart health. A good example of this is dairy. While the fat in dairy foods has a reputation for being bad for blood cholesterol levels, recent studies have found that consuming full-fat dairy foods had either a neutral or beneficial effect on good (HDL) cholesterol.
However, the Heart Foundation still recommends including reduced-fat dairy foods in your diet, rather than full-fat, in order to manage high blood cholesterol levels and blood pressure, and help prevent cardiovascular disease. An added benefit of reduced-fat dairy foods is that they also help you control your kilojoule intake and your weight.
On the surface it may appear that whole milk – which has a total fat content of four per cent – is low in fat compared to other common dairy foods. But whole milk can still be a major source of fat and kilojoules since we use it often – on cereal, in tea and coffee, and in cooking.
For the most part, the only major component missing from reduced-fat dairy products is the fat. Some of the fat-soluble vitamins (such as vitamins A, E, D & K) are also lost, but most manufacturers replenish their products with these vitamins to make sure you aren’t missing out. Additionally, removing the fat from dairy increases the concentration of both calcium and protein, so you get more of these nutrients in reduced-fat dairy products.
Are low-fat foods healthy – or do we just end up eating twice as much of them?
“Half the fat, so you can eat twice as much” said an old TV ad. Sadly, this just isn‘t true. Foods containing less fat are a great addition to the ever-increasing variety of foods in our diet – but only if we don’t eat more of them as a result. It’s also important to remember that some low-fat foods contain extra energy from added sugar – so you may end up eating the same number of kilojoules (or more!) even though you're choosing the low-fat option.
What are the healthiest fats/oils to use?
The best fat or oil depends on how and when it is being used. The key is knowing which fats are healthier and what constitutes a reasonable amount of fat. This could be 1 tablespoon salad dressing, a spray of oil for roasting vegies or 1 teaspoon reduced-fat table spread on a slice of toast.
All oils are almost 100 per cent fat and contain a similar number of kilojoules. Remember, no matter if it’s a ‘good’ or ‘bad’ fat, all fats are higher in energy (37kJ/gram) than carbohydrate and protein (16–17kJ/gram), so should be consumed in moderation.
The bottom line
There is no single food or food group that makes us healthy or unhealthy. It‘s not simply the type of fat we eat that influences body weight; it‘s the total amount and combination of foods – together with staying active – that regulates weight. To help manage your weight, you need to reduce the total amount of fat (and kilojoules) in your diet and ensure the majority of your fat comes from unsaturated fats.
Always choose lean meat and trim visible fat before you cook it.
Choose a canola, sunflower or olive oil reduced-fat table spread, instead of butter.
When cooking, use spray oil wherever possible.
For salad dressings, choose a vegetable or seed oil such as canola, sunflower, olive, soybean, sesame or peanut.
Line trays with baking paper instead of spraying them with oil when baking.
Choose low-fat varieties of foods whenever possible, but always read the labels – watch out for extra kilojoules from added sugar.
Choose reduced-fat or skim dairy foods (milk, yoghurt, cheese, custard and ice-cream).
Eat oily fish 2–3 times per week to get your omega-3s.
When shopping, use the nutrition panel to choose products with ‘a little‘ fat, and avoid those with ‘a lot‘ of fat, wherever possible:
‘A little‘: less than 3g/100g ‘A lot‘: more than 20g/100g
‘A little‘: less than 1g/100g ‘A lot‘: more than 5g/100g
How much fat do I need each day?
There are no definitive recommendations, however based on an 8700kJ diet, suggested daily intakes are:
Total fat: 20–35% total energy intake (about 70g/day)
Saturated fat: Less than 7% total energy intake (about 16g/day)
What to look for on labels
Fat comes in many guises. If any of the ingredients below are in the first 3–5 ingredients on a food label, try to find another option (unless you‘re buying oil!).
Did you know?
A spread must contain 80 per cent fat to be called margarine – a level similar to butter. Reduced-fat table spreads can have as little as 23 per cent fat.
Swapping your daily small cappuccino from full-fat to skim wipes more than 1kg saturated fat from your diet over a year.
Astrup A., et al. 2011. The role of reducing intakes of saturated fat in the prevention of cardiovascular disease: where does the evidence stand in 2010? American Journal of Clinical Nutrition doi: 10.3945/ajcn.110.004622 U.S. Department of Agriculture and U.S. Department of Health and Humans Services. Dietary Guidelines for Americans, 2010. 7th Edition, Washington DC: U.S. Government Printing Office Foster R., Williamson C.S., Lunn J. 2009. Briefing Paper: Culinary oils and their health effects. Nutrition Bulletin; 34(1):4-47 Dairy Australia. 2009. Cardiovascular Health. Available at http://www.dairyaustralia.com.au. Accessed August 2011 Heart Foundation. 2009. Position statement. Dietary fats and dietary sterols for cardiovascular health. Available at URL www.heartfoundation.org.au. Accessed August 2011