AQA GCSE Food Preparation and Nutrition: Revision Guide

2 Book-link: 1.1.2 Fat, pages10–16 Fat Key learning: FAT What it is and what it is made of • Fat is a macronutrient which is found in animal and plant foods • Fats are solid at room temperature • Oils are liquid at room temperature • Fats and oils have the same structure and same energy value • Fat / oil molecules are called triglycerides • A triglyceride looks like this: What fatty acids are Types of fatty acids: • Monounsaturated fatty acid: type of fatty acid found in solid fats and liquid oils • Saturated fatty acids: found mainly in solid fats, e.g. butter, lard, suet, block vegetable fat, ghee, the fat in meat, palm oil, coconut and chocolate Unsaturated fatty acids: found mainly in liquid plant oils such as olive, rapeseed, sunflower and corn; and also oily fish, avocado pears, nuts, seeds and some vegetable fat spreads What fat does in the body (its functions) • Gives energy which is stored in the body • 1g fat gives 9 kcals / 37kJ • Insulates the body from the cold • Protects bones and kidneys from physical damage • Provides vitamins A, D, E, K • Fat is stored mainly in adipose tissue cells under the skin • Adipose tissue insulates the body from the cold and provides a ‘cushion’ to protect the bones and kidneys • The body breaks down the fat stores to release energy if there is not enough available from carbohydrate • Vitamins A, D, E and K are known as ‘fat soluble’ vitamins Which foods give us fat (sources of fat) • Visible fats and oils: fats / oils in a food that you can easily see: e.g. fat in meat, oil in tuna, butter, lard, suet, block vegetable fat, ghee, plant oils such as olive, palm, sunflower oil • Invisible fats and oils: fats / oils in a food that you cannot easily see: e.g. in cakes, pastries, potato crisps, biscuits, chocolate, nuts, fried foods, meat products, etc. • Foods containing fat are energy dense • It is easy to consume a lot of energy from these foods without realising it as they are very palatable (tasty) and easy to eat What happens if you do not have enough fat (a de ciency) Rare in the UK, but deficiency causes: • Weight loss • Feeling cold • Bruising of bones if knocked • Lack of vitamins A, D, E, K • The body prefers to use carbohydrate for energy • If it does not have enough energy from food, the body will use up the stores of fat from adipose tissue and elsewhere in the body What you must know about fat In your answers, you need to know how to explain: Further information you can add to extend your answers: 339 Chapter 1: Nutrients : Fat