AQA GCSE Food Preparation and Nutrition: Revision Guide

T HEORY I NTO P RACTICE – try this practical challenge Q UESTIONS Using your knowledge of nutrients and dietary guidelines, answer these questions: • Using your nutritional analysis to help you, explain how the meal you have planned meets the dietary guidelines for teenagers. (3 marks) • Explain what time-saving methods you have used to prepare and cook the meal within the time allowed. (3 marks) What do you need to know? You now know about the dietary guidelines for a healthy balanced diet . Next you need to know: • The importance of energy in the diet • How we get energy from food • Why the body needs energy • Why energy balance is important Key learning: Energy in the body and in the diet Functions of energy in the body Energy is needed by the body for: • Growth • Movement • Body warmth • Production of sound • Brain function • Chemical reactions • Energy is measured in either kilocalories (kcals) or kilojoules (kJ) • 1 kcal = 4.2kJ Main sources of energy in the diet • Carbohydrate • Fat • Protein • 1g pure carbohydrate = 3.75 kcal / 16kJ • 1g pure fat = 9 kcal / 37kJ • 1g pure protein = 4 kcal / 16kJ • Energy from excess carbohydrates converts into fat in the body • Glucose is the form in which energy is used in the body • Fats and oils have the same energy value • Fat is a store of energy in the body • Fat is converted into glucose in the body when there is not enough carbohydrate available • Protein is only used for energy if there is not enough carbohydrate or fat available • Foods containing a lot of fat and sugar are called energy dense Plan and make a tasty and balanced two-course evening meal for two teenagers, which can be prepared, cooked and served in 30 minutes. Carry out a nutritional analysis of the meal. 2 Energy needs Book-link: 1.2.2 Energy needs, pages 58–62 What you must know about energy in the body In your answers, you need to know how to explain: Further information you can add to extend your answers: 33 5 Chapter 2: Nutritional needs and health : Energy needs