Gone are the days of fat phobia. We need good fats for our health and wellbeing. Today I thought I’d give you a wee bit of a lesson (I promise it won’t be complicated and school-like!) on fats. So sit down with a cuppa and have a read on what you need to know about fat. We’ll be taking a look at at what fats are, why we need them, how much fat we need, and what are healthy fats?
What are fats?
Fats are one of the three types of macronutrients that food is made from, the other two being carbohydrate and protein. There are three main types of fat; polyunsaturated, monounsaturated and saturated fats. Trans fats is another type of fat that is found in very small amounts in nature, and is made in manufacturing. Processed trans fats are bad news when it comes to your health as they decrease your good cholesterol and increase your ‘bad’cholesterol.
One type of fat usually dominates in a food for example, butter is mainly saturated fat and olive oil is mainly monounsaturated. All fats contain approximately the same amount of kilojoules/calories – around 37kj or 9 calories. Fat is energy dense compared to the other macronutrients, carbohydrate and protein, which both have 17kj or 4 calories.
Whilst we talk about fats in terms of saturated, monounsaturated and polyunsaturated, these different fats are made up of building blocks called fatty acids.
For example, there are different saturated fatty acids within each main type of fat. Lauric acid is a fatty acid found in coconut oil.
If you’re keen to know what are healthy fats, we’ll talk more about this further on.
Why do we need fat?
Fats are essential for life and play an important part in nutrition:
* Some of the vitamins we need can only be absorbed in the presence of fat. The fat soluble vitamins are: Vitamin A – Vitamin E – Vitamin D- Vitamin K-
* We need fat to help us absorb some fat soluble antioxidants such as lycopene and beta carotene.
* Essential fatty acids are needed for a range of processes in the body. They are an important part of our cell membranes and are used to make many other substances in the body, including those involved with regulating inflammation.
* Fats provide a source of energy
* Fats are needed to produce hormones.
How much do we need?
The Ministry of Health recommends that 33% of our energy intake comes from fat, and that no more than 10% of this should come from saturated fat. This isn’t a ‘rule’, rather a guideline.
It is possible to have a healthy diet with a higher fat percentage. A Mediterranean style diet contains around 40% of fat and this is linked to a lower rate of cardiovascular disease and other diseases. This diet is low in saturated fat, with fat sources mainly from olive oil, nuts. The Mediterranean diet is also is rich in omega 3 fats from seafood.
Because we’re not all sitting around with calculators to work out percentages of fat in our diet, most of us will get enough fat through the foods we eat and the oils we use for cooking.
In general, a small/medium amount at most meals is enough but each individuals needs differ. Some people do better on a higher fat diet, others don’t.
What are healthy fats?
The evidence at the moment points towards unsaturated fats being the best for our health. These are polyunsaturated fats, in particular the omega 3 fats, and also monounsaturated fats
These are found in nuts, seeds, avocado, oily fish, olives and oils made from these ingredients.
In the polyunsaturated fat group, omega 3 and omega 6 fats are essential fatty acids that need to be supplied by the diet. Our bodies can form other fatty acids it needs from other fat sources, but the omega 3 and 6 fats must be supplied in our diet – hence being essential. In the modern western diet, we tend to get plenty of omega 6 fats, but not enough omega 3 fatty acids.
Omega 3 fatty acids are found in oily fish and seafood, as well as in plant based sources such as chia seeds, linseeds, walnuts and canola oil. Marine/animal based omega 3 fats are the type that our body uses most readily, but plant based omega 3 fats are also useful to include in the diet.
Omega 3 fats are an important component of every cell in our body and have important anti-inflammatory properties. You can get your weekly intake by including oily fish 2-3 times a week. You can read more about omega 3 fats here.
What about saturated fat?
I’m sure you’ve all noticed that saturated fat has been back in the headlines, with titles such as “butter’s back” gracing the cover of many publications. But whilst saturated fat isn’t the dietary villain we once thought, it doesn’t mean it’s suddenly a superfood either.
The saturated fat story is more complicated than first thought. What we really need to look at is the whole food, and the dietary pattern. In the low fat food era, focusing on just the nutrient meant food companies removed fat and added sugar to improve taste – no fat, then it must be healthy right? Wrong! We all know that eating refined, sugary carbohydrates is not a great idea for health, and in removing fat and replacing it with refined carbohydrate, no health gains were made.
If we look at this from a wholefoods approach, switching your meat pie for white bread sandwiches won’t lower your risk for heart disease, but going for salmon with greens is likely to.
Most of our fat sources should come from foods such as nuts, avocado, plant based oils such as olive oil as well as including oily fish for omega 3 fats.
Saturated fats can increase LDL cholesterol levels and high LDL cholesterol is one risk factor for heart disease. Saturated fats do not cause heart disease, but we do want to be mindful about the quantities we consume.
Because we don’t just eat ‘saturated fat’, we eat foods, it’s useful to think about it from a wholefoods perspective. From a whole foods perspective, it’s fine to enjoy some meat (still pick lean cuts), a little cheese and other dairy products like milk and yoghurt, while we should aim to reduce intake of processed foods such as biscuits, cakes and pastries. (Side note: cheese and other full fat dairy might not raise cholesterol as once thought, but butter and cream does. It might be that the other nutrients present in milk/cheese are protective against increased cholesterol.)
The other thing about saturated fats is that they are very rigid and compacted (think solid butter vs liquid olive oil). Fats are an essential part of our cell membranes, which we want to be more fluid so nutrients and messengers can be transported easily. The more saturated fats there are in the cell membrane, the less fluid it will be. This is another reason why we should still be mindful of saturated fat intake.
It doesn’t mean we should never eat them, but don’t go overboard and choose unsaturated more than saturated.
What oils should I cook with?
I’m a fan of olive oil for most of my cooking. I also use avocado oil, macadamia nut oil and sometimes coconut oil. Olive oil actually has a fairly high smoke point, and is fine to use for most cooking. You can read more about my choices of oils here.
So fat doesn’t make you fat?
One thing I heard a lot is “fat doesn’t make you fat!”. Well it’s true, it doesn’t. Nothing in itself makes you fat. Not cupcakes. Not chocolate. Not cheese. What makes you gain weight is consuming more calories than your body uses. There are of course other factors that come into play, but a general rule, you need to be consuming more calories than you are using over a period of time to gain weight.
Fat is energy dense. It doesn’t make you fat, but when it comes to weight, you do need to balance your portions. If you eat more than you need, you will gain weight (just as with any other food).
Hopefully this post has been useful in answering the question what are healthy fats? Over the next few weeks I’ll be posting a similar article on carbohydrates and protein.