Fats can be visible in some foods such as a fat layer on the outside of lamb or pork. Sometimes you can see the fat inside meat as a white marbling. Visible fat is the butter on a slice of bread.
Some fats are invisible and cannot be seen easily because they have been used to make the product. Crisps, biscuits and cakes contain invisible fat.
Some liquid food such as milk, egg yolks, mayonnaise and gravies contain fat droplets which are difficult to see. When fat droplets are distributed in the water we call this an emulsion.
Animal sources: butter, ghee, lard, goose fat, suet, dripping, meat: beef, lamb, chicken etc., meat products: sausages, chorizo, burgers, oily fish: tuna, salmon, full-fat Greek yoghurts, hard cheese, cream, eggs, chocolate, pastries, biscuits and cakes.
Vegetable sources: vegetable and plant oils: olive, sunflower, rapeseed, avocados and olives, nuts and nut products, seeds, fat spreads.
Hydrogenation is the chemical process when vegetable oils are ‘hardened’, to make them solid at room temperature. Partially hydrogenated vegetable oils may contain trans fats. These are thought to cause health problems such as heart disease.
Food manufacturers are being encouraged to reduce the amount of hydrogenated fat in our food. Only 2% of our daily energy should come from trans fats, this is no more than about 5g of fat a day.