Functions of fat
- A concentrated source of energy: 1 g of fat provides 9 kcal.
- Insulation (a layer under the skin keeps the body warm) and protection of vital organs.
- Provides fat-soluble vitamins A, D, E and K, and essential fatty acids.
Types of fat
- Saturated fats are mostly from animal sources and are solid at room temperature: butter, lard, cheese, fatty meat, and also coconut and palm oil. They can raise blood cholesterol.
- Unsaturated fats are mostly from plants and are usually liquid at room temperature.
- Monounsaturated fats: olive oil, rapeseed oil and avocados. Polyunsaturated fats: sunflower oil, nuts, seeds and oily fish (which contain omega-3 fatty acids).
- Unsaturated fats are healthier and can help lower cholesterol.
- Visible fats can be seen (the fat on bacon); invisible fats are hidden in foods (in cakes, biscuits and crisps).
Too little or too much
- Excess: weight gain and obesity, high cholesterol, and a higher risk of coronary heart disease and stroke.
- Deficiency: a lack of fat-soluble vitamins, feeling cold, and low energy.
- Adults should get no more than about 35% of their energy from fat, and cut down on saturated fat.
Key terms
- Saturated fat
- Fat mostly from animals, solid at room temperature.
- Unsaturated fat
- Fat mostly from plants, usually liquid at room temperature.
- Cholesterol
- A fatty substance in the blood; high levels increase heart disease risk.
- Omega-3
- A type of polyunsaturated fatty acid found in oily fish.
- Invisible fat
- Fat that can't be seen in a food, such as in cakes.
- Fat-soluble vitamins
- Vitamins A, D, E and K, carried by fat.