What is fat?
Fats are made up from 3 fatty acids (chains of carbon and hydrogen) attached to a glycerol backbone. There are many different types of fatty acids, grouped according to their length (how many carbons are in the chain) and their bonding (how the carbons are attached together).
You may have heard the term ‘good’ and ‘bad’ fats, which can often confuse people. ‘Good’ fats, also called monounsaturated and polyunsaturated fatty acids, whereas ‘bad’ fats are called saturated fatty acids. A common misconception is that ‘bad’ fats are higher in energy than ‘good’ ones, but all are approximately 9 calories per gram. The terms ‘good’ and ‘bad’ actually originate from their effect on the heart and blood cholesterol levels.
Where does fat come from?
Fats have a creamy, palpable texture; thus, high fat foods often have this texture too! Monounsaturated and polyunsaturated fatty acids are normally from plant sources such as nuts, oils and vegetables such as avocados as well as marine sources including fish and seaweed. Saturated fatty acids, originate from animal sources such as red meat and high fat dairy including cream and butter. The term ‘lean meat’ refers to meat sources that are low in saturated fatty acids, such as poultry.
How much fat do we need?
As fat is higher in calories than protein and carbohydrate, an excessively high fat intake can quickly lead to weight gain. It is currently recommended that fat should contribute to less than 35% of our daily energy intake; that equates to 700 kcal and 875 kcal for women and men respectively. Saturated fatty acids should make up a maximum of 10% of our energy intake (200kcal for women and 250kcal for men), whilst polyunsaturated should contribute 6-11% of the energy content of the diet (120-220 kcal per day for women and 150-275 kcal per day for men). No recommendations for monounsaturated fatty acids are currently set.