We have whizzed through what are carbohydrates and the importance of protein. Fat is another macronutrient that is essential in our diet. However, for a long time the idea of a low fat diet has been thought to be the key to greater weight loss (as has a million other fad diets!). The marketing of many “healthy” products involves branding them as low in fat; the fat content may be reduced and calories numbers in low figures but the nutrients within the product are sucked out. Let’s talk about fat to better inform ourselves of what fats are, why we need them and where we should be getting them from in our diet.
What are Fats?
All fats are made up of fatty acids as a simple building block. How these fatty acids are joined together affects the structure and function of the fat. There are 3 types of fats: Saturated, Unsaturated (further broken down to monounsaturated and polyunsaturated) and transfats.
- Monounsaturated fats: Found in olive oil, avocados and nuts. This type of fat is known to help reduce LDL cholesterol, also known as the bad cholesterol. As a result, monounsaturated fats have a role to play in reducing the risk of heart disease, atherosclerosis and high blood pressure.
- Polyunsaturated fats: Found in oily fish, walnuts, flaxseeds and vegetable oils. Omega 3 and 6 are the two main polyunsaturated fats found in our diets; we do not make these in our body and therefore can only attain them from our food. In the Western diet, we tend to eat plenty of Omega 6 however fall short on Omega 3, which has important anti-inflammation characteristics. Omega 3 is found in oily fish such as salmon and tuna.
- Found in butter and coconut oil, full fat dairy, meat
- While saturated fats do raise the LDL cholesterol, they also help raise the good cholesterol, HDL cholesterol.
- Flawed data in historical studies lead to this belief that saturated fats are linked to cardiovascular disease. This has since been debunked by further research that has been done.
- Like with all fats, saturated fats should be eaten in moderation.
- Found in biscuits, sweets, margarine and fried foods.
- Transfats are fats formed through artificially hardening unsaturated fats, which are often found in liquid form. The process allows for companies to improve the texture and prolong shelf life allowing them to gain more profit on their product.
- Transfats increase LDL cholesterol, reduce HDL cholesterol and increase weight gain.
Why do we need Fats?
Fat has a number of different functions in the body:
- Energy source: like carbohydrates, fats are a source of energy for the body. They can also be stored for times when energy levels drop.
- Brain: In a recent post, I talked about mental health and the effect fats have on the brain function. Essential fatty acids, Omega 3 and Omega 6, help to influence mood and allow for better brain performance and memory
- Nerves: Our nerves have a key fatty component called the myelin sheath. Myelin sheath allows for electrical messages to be conducted around the body.
- Absorption: Many nutrients such as Vitamins A, D, E and K require fat in order for them to be absorbed.
- Insulation: We all have fat cells deposited in our tissue to help sustain and maintain body temperature.
How much fat do we need?
Fat provides 9 calories per 1g
In the UK, guidelines suggest no more than 35% of the total daily calories should come from fat and only 11% of this should be from saturated fats. How can this be applied practically without becoming obsessed with numbers?
- Avoid trans fats found in processed foods
- Eat foods rich in monounsaturated and polyunsaturated fats, focusing on increasing omega 3
- Choose saturated fat that is from high quality foods: full fat greek yogurt, grass-fed meat, dark chocolate, ghee and coconut oil.