If you learnt about food and nutrition back in the 80’s and 90’s, then for sure, this is what you would have been taught. Even today fats are such a confusing topic because there are so many conflicting thoughts on fats and health.
Over the years you’ve probably heard things like these:
- Fat that passes our lips ends up on our hips
- The fat you eat is the fat you wear
- The fatty accumulations in our arteries that cause heart attacks come from dietary fat and cholesterol
Some of these beliefs come from the paradigm that calories are ‘the be all and end all’ when it comes to health and weight. It is true that 1 gram of fat has 9 calories whereas 1 gram of carbohydrates only has 4 calories. This is likely where many of these old dietary theories came from, resulting in the advice to avoid fat as much as possible. But this advice is, in fact, far from ideal. We need fat in our diet. It is important for many bodily functions, including helping us burn body fat, boosting our metabolism, lowering our triglyceride levels and decreasing the risk of diabetes, heart disease and obesity.
A 2012 Harvard study found that a very-high-fat diet, compared to a very-low-fat diet, speeds up metabolism, resulting in 300 more calories being burned in a day. Talk about the metabolism boosting benefits of fat! Does this, however, mean we should all rush out and eat way more fat? The answer is probably not. But we do need more of the right types of fats in our diet to promote optimal health.
We still want to stay away from trans fats. These are pro-inflammatory and negatively impact our health. Trans fats are created through a chemical process called hydrogenation, which is when liquid oils are turned into semi-solid oils like margarine. They do naturally occur in some foods too, but in small quantities. It is the hydrogenated oils that are most problematic.
The healthy fats we want to include more of are the monounsaturated fats, such as those found in olive oil, avocados, avocado oil, flaxseed oil, nuts and seeds. Always look for oils that are cold pressed, and ideally organic. Even with monounsaturated fats, there are some that are best avoided. For example, canola oil is a popular cooking oil, but I consider this to be an unhealthy refined food.
The key to knowing which is going to be helpful and which is harmful has to do with the way these oils are processed. Canola oil needs to be heated to a high temperature, bleached with strong chemicals and deodorised, which oxidises and damages the oil. It’s best to avoid canola oil and other oils that are not cold pressed, or expeller pressed.
Polyunsaturated fats such as those found in foods like fish, walnuts, eggs and chia seeds are also beneficial. These types of fats show positive health benefits for immunity, cardiovascular functioning, inflammatory issues and brain function.
Saturated fats are found in meat products, dairy, coconut oil and palm oil. We used to think of these as problematic fats but eaten in moderation they can be beneficial for proper hormone and immune system function.
Benefits of eating fats:
- Including fat containing foods in our meals helps the body absorb the fat-soluble vitamins like A, D, E and K. These vitamins are then stored in the liver and in the cells, and are released slowly over time, as needed. The fat soluble vitamins are important for immune function, hormonal balance and general wellbeing.
- Eating a portion of fat in our meals actually increases our metabolism, which improves energy levels, so less fatigue.
- Meals containing fat can help us feel full for longer. Fats have a complex chemical structure which takes more time for enzymes to break down, leading to us feeling satiated for longer.
How much fat should we eat?
Firstly, I suggest not living in fear of fats in the diet. They make food taste better, offer nutritional benefits, help us feel full for longer and improve metabolism. But I also suggest not going crazy with fats either.
Aim to get your fats from whole food sources, such as meat, fish, poultry, eggs, dairy, avocado, nuts, seeds, extra virgin olive oil, grass-fed butter, ghee and cold pressed oils like flaxseed oil, pumpkin seed oil, hemp oil, walnut oil and evening primrose oil. Aim to have some sort of fat containing food at every meal.
Which oils are best avoided?
It is best to avoid canola oil, corn oil, soybean oil, peanut oil, vegetable oil, margarine, shortening, and anything that says ‘hydrogenised’ on it.