Good fats? Bad fats? There is so much speculation about what we should and shouldn’t be eating when it comes to fats. Here are some facts to help you along the way.
What are fats?
Fats are a class of nutrients that are collectively known as lipids. Lipids fall into three categories; triglycerides (fats and oils), phospholipids (lecithin) and sterols (cholesterol).
Triglycerides are the ones we commonly know as saturated, monounsaturated and polyunsaturated (omega 3 and omega 6) fatty acids.
Saturated fats are typically found in meat, dairy products and processed foods. They are solid at room temperature (think lard!). Watch out for hydrogenated and trans fatty acids, these are highly processed and give a longer shelf life. You’ll commonly find these fats in margarine and lots of other processed foods such as cakes, pies and fast food.
Saturated fats should be eaten sparingly. They are a huge contributor to the growing numbers of heart disease and type two diabetes globally. Both diseases can be avoided with the right nutrition.
Monounsaturated fats are found in avocados, nuts and olive oil and are liquid at room temperature. Benefits of monounsaturated fats are the improvement of memory and lipoprotein profiles (increasing good cholesterol and lowering bad). They also help to protect against heart disease.
Polyunsaturated fats are more commonly talked about as omega 3 and omega 6 fatty acids.
Omega 3 protects against inflammation in the body. Omega 6 has both inflammatory and pro-inflammatory qualities. When omega 6 is consumed from animal products (meat, dairy and eggs), it has a pro-inflammatory effect caused by arachidonic acid content. Omega 6 from plant sources have an anti-inflammatory effect.
Good sources of omega 3 include walnuts and flaxseed and for omega 6, good sources are sunflower and sesame seeds.
Phospholipids provide structure to all body cells. So that makes them pretty important right? Not only do they provide structure, they also help to form components of bile allowing the breakdown of fats during digestion. Phospholipids are found naturally in foods such as eggs, soybeans and peanuts.
The most important sterol you want to know about is cholesterol, in particular, the good (HDL), and the bad (LDL). To put it simply good (HDL) cholesterol helps to decrease bad (LDL) cholesterol by essentially ‘cleaning’ out cells and returning bad (LDL) to the liver for excretion.
Bad (LDL) cholesterol increases the risk of heart disease and good (HDL) cholesterol helps to protect you against heart disease and atherosclerosis. Bad (LDL) cholesterol is found in high quantities in eggs, prawns, beef and chicken.
Foods such as olive oil, legumes and flaxseed increase good (HDL) cholesterol, so it is recommended to keep high (LDL) bad cholesterol foods to a minimum.
How much fat should I consume every day?
Fats should provide at least 20-35% of your daily kilojoule/calorie intake with an absolute minimum of this coming from saturated fats.
You should opt for fats coming from whole foods, which will provide sources of monounsaturated fats and polyunsaturated fats. A good tip when buying foods is to read the food label and notice what % of fat is coming from saturated, monounsaturated or polyunsaturated sources. You’ll notice that saturated fats are in more foods than you realise.
Are fats good or bad for me?
As you’ll have read above, there are many benefits to fat consumption and the key to eating fats is making sure you are eating the right ones. Avoid saturated and trans-fats and enjoy eating monounsaturated and polyunsaturated fats. Any excess consumption of saturated fats will lead to possible weight gain and increased health risks.
Are low-fat foods a better option?
Low-fat foods may seem like a good idea, but often their ‘low fat’ content has been replaced by other alternatives to keep the flavour and satiety. Added sugar is the main culprit, so I’d recommend reading food labels to check what the item has been substituted with. Milk and yoghurts are common culprits of this. You’ll notice that sugar content is much higher in low-fat options than their full-fat counterparts.
Have you got a question that hasn’t been covered? You are more than welcome to contact me and I’ll see if it’s something that can feature in the series.
Whitney, E, Rolfes, SR, Crowe, T, Cameron-Smith, D & Walsh, A 2014, Understanding Nutrition: Australia and New Zealand Edition, 2nd edn, Cengage Learning Australia, South Melbourne.