CCEA GCSE HOME ECONOMICS FOOD AND NUTRITION. Nicola Anderson Claire Thomson

Transcription

1 CCEA GCSE HOME ECONOMICS FOOD AND NUTRITION SAMPLE MATERIAL We are working closely with CCEA for endorsement of this Student Book for the new GCSE in Home Economics Nicola Anderson Claire Thomson

2 Fully updated to cover the 2017 CCEA Home Economics: Food and Nutrition GCSE specification, this new edition of the market-leading textbook will guide your students through the content, prepare them for assessment and help you deliver an engaging, cost-effective Home Economics: Food and Nutrition course. We are working towards endorsement with CCEA of the following print resource, which supports the teaching and learning of the new GCSE Home Economics: Food and Nutrition resources CCEA GCSE Home Economics:, Food and Nutrition Student Book June Visit to pre-order your class sets or to sign up for your Inspection Copies or einspection Copies. Also available: CCEA GCSE Home Economics: Food and Nutrition etextbooks Whiteboard etextbooks are online interactive versions of the printed textbook for front-of-class teaching. From 150. Student etextbooks are downloadable versions of the printed textbook that are assigned to individual students. From 5.49 per student. Sign up for a free 30 day trial visit dynamiclearning Extra support for your course: Free online planning support Coming soon For more information, contact Mary McGurk, Accounts Manager for Northern Ireland To find out more and request Inspection Copies, einspection Copies and free, no obligation 30-day Dynamic Learning trials, visit To place an order, contact Mary McGurk, Accounts Manager for Northern Ireland mary.mcgurk@hodder.co.uk Tel:

3 CCEA GCSE HOME ECONOMICS FOOD AND NUTRITION Nicola Anderson Claire Thomson

4 Photo credits: p.1 belchonock - 123RF; p.2 Africa Studio - Fotolia.com, (c) Raphotography Dreamstime. com; p.3 Vikram Raghuvanshi / istockphoto.com; p.4 CharlieAJA - istock - Thinkstock/Getty Images, Sirfuji - istockphoto via Thinkstock/Getty Images, kovalchuk - istock Thinkstock/Getty Images; p.5 (c) Griffin024 Dreamstime.com; p.6 chrisdorney Shutterstock, David J. Green - food themes / Alamy Stock Photo, Newscast Online / Alamy Stock Photo Every effort has been made to trace all copyright holders, but if any have been inadvertently overlooked, the Publishers will be pleased to make the necessary arrangements at the first opportunity. Although every effort has been made to ensure that website addresses are correct at time of going to press, Hodder Education cannot be held responsible for the content of any website mentioned in this book. It is sometimes possible to find a relocated web page by typing in the address of the home page for a website in the URL window of your browser. Hachette UK s policy is to use papers that are natural, renewable and recyclable products and made from wood grown in sustainable forests. The logging and manufacturing processes are expected to conform to the environmental regulations of the country of origin. Orders: please contact Bookpoint Ltd, 130 Milton Park, Abingdon, Oxon OX14 4SB. Telephone: +44 (0) Fax: +44 (0) education@bookpoint.co.uk Lines are open from 9 a.m. to 5 p.m., Monday to Saturday, with a 24-hour message answering service. You can also order through our website: ISBN: Nicola Anderson and Claire Thomson 2017 First published in 2016 by Hodder Education, An Hachette UK Company Carmelite House 50 Victoria Embankment London EC4Y 0DZ Impression number Year All rights reserved. Apart from any use permitted under UK copyright law, no part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording, or held within any information storage and retrieval system, without permission in writing from the publisher or under licence from the Copyright Licensing Agency Limited. Further details of such licences (for reprographic reproduction) may be obtained from the Copyright Licensing Agency Limited, Saffron House, 6 10 Kirby Street, London EC1N 8TS. Cover photo ewastudio / 123RF.com A catalogue record for this title is available from the British Library.

5 CONTENTS Introduction to CCEA GCSE Home Economics: Food and Nutrition How to use this book Chapter 1 Food provenance Chapter 2 Food processing and production Chapter 3 Food and nutrition for good health Chapter 4 Energy and nutrients Chapter 5 Macronutrients Chapter 6 Micronutrients Chapter 7 Fibre Chapter 8 Water Chapter 9 Nutritional and dietary needs Chapter 10 Priority health issues Chapter 11 Being an effective consumer when shopping for food Chapter 12 Factors affecting food choice Chapter 13 Food safety Chapter 14 Resource management Chapter 15 Food preparation, cooking and presentation skills Chapter 16 Controlled assessment: Practical Food and Nutrition Chapter 17 Preparing for the written paper: Food and Nutrition Glossary Answers to Review questions Index 5

6 CHAPTER 5 MACRONUTRIENTS What will I learn? You should be able to: u explain the functions and identify the main sources of the following macronutrients: protein (to include biological value and complementation) fat: saturated and unsaturated (to include monounsaturated and polyunsaturated) carbohydrates: sugars (simple) and starches (complex). Macronutrients are nutrients required in large amounts in the diet. Protein, fat and carbohydrates are all macronutrients. Protein Protein is a macronutrient, needed in the body for a range of functions. Protein are the basis of body structures such as muscles, skin and hair. Functions of protein u They are needed to facilitate growth, particularly during pregnancy, childhood and adolescence. u They help to repair damaged body tissues or recover after illness. u They help to maintain body tissue, for example muscle, hair and skin. u They produce enzymes for digestion. u They produce hormones which regulate body functions. u They provide a secondary source of energy (1 g provides 4 kcal). Sources Proteins are available from animal sources and plant sources. Novel proteins are alternative protein foods. Table 5.1 Sources of protein Animal protein Plant protein Novel protein Meat Fish Eggs Dairy products Pulses Beans Grains Nuts Tofu Soya Quorn Tempeh 1

7 CHAPTER 5 MACRONUTRIENTS Protein quality Proteins are composed of units called amino acids, which are classified as: u dispensable amino acids, which can be produced in the body u indispensable amino acids, which cannot be made in the body and so must be provided by the diet. For this reason indispensable amino acids are often called essential amino acids. Humans need approximately 20 amino acids, and eight of these are indispensable. The quality of the protein eaten is important and depends on the amino acids that are present. If a food contains all the indispensable amino acids in the approximate proportions required by humans, it is said to have a high biological value (HBV). A food that lacks one or more of the indispensable amino acids is said to have a low biological value (LBV). Figure 5.1 All these foods are sources of protein. Proteins from animal sources have a higher biological value than proteins from plant sources. The exceptions to this rule are gelatine, an animal protein with low biological value (LBV), and soya, a plant protein with high biological value (HBV). Complimentary action of proteins Figure 5.2 Separately, baked beans and toast each have a low biological value. However, combining them results in a meal of high biological value. LBV proteins lack one or more of the indispensable amino acids. This is called the limiting amino acid and it varies in different proteins. When two LBV protein foods, such as a pulse and a cereal, are eaten at a meal (for example, beans on toast, or lentil soup with bread), the amino acid in one food will compensate for the limiting amino acid of the other, resulting in a meal of high biological value. This is known as complementation (the complementary action of proteins). 2

8 Protein Complementation is particularly relevant for people who exclude animal products from their diet, for example, vegetarians and vegans. As long as a variety of LBV proteins is eaten in combination, the quality of their protein intake can be as good as that of someone who eats HBV foods. Activity 1 Use food tables to find out the following. 1 Record the protein content of five animal foods as grams (g) of protein per 100 g of food. 2 Record the protein content of five plant foods as grams (g) of protein per 100 g of food. 3 Record the protein content of five novel foods as grams (g) of protein per 100 g of food. Figure 5.3 LBV proteins Activity 2 1 Plan a main meal that would meet the protein needs of one of the following: a pregnant woman, a school-aged child, or an adolescent. 2 Complete a nutritional analysis by calculating the protein content of the meal. 3 Consult Dietary Reference Values (DRVs) to determine what percentage of your chosen individual s protein requirements would be met by consuming one portion of this meal. Stretch and challenge 1 Design a taste test to evaluate the sensory qualities of a range of novel proteins. Consider the criteria to assess the novel protein foods. Key words Macronutrients nutrients required in large amounts in the diet (fat, carbohydrate and protein). Protein a macronutrient needed in the body for a range of functions including growth and repair. Biological value the quality of the protein eaten, depending on the amino acids present. Amino acids units that join together to make proteins. Dispensable amino acids amino acids which can be produced in the body. Indispensable amino acids amino acids which cannot be made in the body and must be provided by the diet. High biological value (HBV) a food that contains all the indispensable amino acids. Low biological value (LBV) a food that lacks one or more of the indispensable amino acids. Complementation the combining of LBV proteins eaten in one meal that provide all the essential amino acids. 3

9 CHAPTER 5 MACRONUTRIENTS Fat Fat is a macronutrient, needed in the body for a range of functions. Figure 5.4 Sources of saturated fat in the diet Figure 5.5 Unsaturated fatty acids could take more hydrogen atoms by breaking the double bonds and adding hydrogen. Clear, accessible explanations of all subject content Functions of fat u Fat provides a concentrated source of energy (1 g provides 9 kcal). u It insulates the body to stop it losing heat. u It protects organs and bones against damage. u It forms the structure of body cells. u It is a source of fat-soluble vitamins A and D. u It is a source of the essential fatty acids omega 3 and omega 6. The body needs some fat to meet its energy requirements. Not more than 35 per cent of dietary energy should come from total fat, with no more than 11 per cent of this dietary energy coming from saturated fat. Saturated and unsaturated fats Fats are made up of carbon, hydrogen and oxygen atoms. They are composed of fatty acids and glycerol. How these molecules are combined determine the type of fat: saturated fat or unsaturated fat. Saturated fats, such as butter and lard, are typically solid at room temperature and are mainly found in foods from animal sources. A diet high in saturated fat has been associated with raised blood cholesterol levels, which is a risk factor for cardiovascular disease (CVD). Unsaturated fats, such as olive oil or sunflower oil, are typically liquid at room temperature and are mainly from plant sources. Many studies have shown that unsaturated fats are better for health. There are two types of unsaturated fat: u Monounsaturated fats have one unsaturated double bond in the molecule. u Polyunsaturated fats have two or more double bonds in the molecule. Sources of fat Table 5.2 Sources of fat Saturated fat Monounsaturated fat Unsaturated fat Polyunsaturated fat Figure 5.6 Sources of monounsaturated fat Meat Eggs Dairy products Butter Vegetable oils, e.g. olive oil and rapeseed oil Nuts Olives Avocado Oily fish Meat Margarine Vegetable oils, e.g. sunflower Seeds 4

10 Fat Essential fatty acids (EFAs) Fats are composed of fatty acids. The body can make all of the fatty acids it needs except for two, known as omega 3 and omega 6. These are called essential fatty acids (EFAs) and must be provided in the diet. u Omega 3 fatty acids can help prevent blood clotting which helps protect the heart and can reduce the risk of cardiovascular disease (CVD). Oily fish are a good source of omega 3 essential fatty acids. u In moderation, omega 6 can have a positive impact on blood cholesterol which can reduce the risk of cardiovascular disease (CVD). Vegetable oils are a good source of omega 6 essential fatty acids. Figure 5.7 Oily fish, such as mackerel, are a source of omega 3 fatty acids. Activity 3 The fat content of food is greatly increased if certain cooking methods or other ingredients are added to them. For example, potatoes boiled in water have much less fat per 100 g than 100 g of chips or potato crisps. Create an infographic, postcard or flyer that supermarkets could use to promote low-fat cooking tips. Figure 5.8 5

11 CHAPTER 5 MACRONUTRIENTS Activity 4 1 Plan and make a reduced-fat version of a popular fast-food meal or a readymade meal. 2 Carry out a nutritional analysis of your recipe. Comment on the fat content of your reduced-fat recipe compared with the fast-food or ready-made version. 3 Carry out a taste test to evaluate the sensory qualities of your reduced-fat recipe. Activity 5 Compare the total fat and saturated fat in 100 g of a range of foods for example, a standard version of a product such as mayonnaise, crisps, biscuits or cheese with a reduced-fat version. Would you buy this product? Explain your decision. Helps students apply their understanding of food and nutrition with engaging activities Figure 5.9 Differentiates with stretch and challenge activities to ensure progression and to challenge more able learners Ensures your students understand even the most challenging topics with clear, accessible explanations of all subject content and simple definitions of key words Stretch and challenge 2 Media review: Research and record key facts about essential fatty acids and how they benefit health. Present your findings. Key words Fat a macronutrient needed in the body for a range of functions including warmth and energy. Saturated fat fat mainly from animal sources, typically solid at room temperature; examples include butter and lard. Unsaturated fat fats mainly from plant sources, typically liquid at room temperature; examples include olive oil and sunflower oil. Monounsaturated fat a type of unsaturated fat, with one unsaturated double bond in the molecule. Polyunsaturated fat a type of unsaturated fat with two or more one double bonds in the molecule. Essential fatty acids fatty acids such as omega 3 and omega 6 that must be supplied in the diet as the body cannot produce them. 6

12 Carbohydrate Carbohydrate Carbohydrate is a macronutrient, needed in the body for a range of functions. Functions of carbohydrate u It provides the body with energy (1 g provides 3.75 kcal). u It has an protein-sparing effect, so that protein is used for growth and repair rather than energy. u It provides fibre to aid digestion and prevent bowel disorders. Sources of carbohydrate Table 5.3 Sources of carbohydrate Sugars Table sugar Confectionary Cakes and biscuits Honey Fruit juice Starches Grains Cereals Pasta Rice Some fruit and vegetables, e.g. banana and potatoes The difference between the two types of carbohydrates is important. Sugars are absorbed quickly by the body, and raise blood sugar levels rapidly. Sugars are a simple form of carbohydrate. Starches take longer to digest and absorb; they are complex carbohydrates. They have a positive impact on keeping blood sugar levels constant. Starchy carbohydrates are also a valuable source of fibre. The body needs a supply of carbohydrate to meet its energy requirements. About 50 per cent of dietary energy should come from carbohydrates, with no more than 5 per cent of this dietary energy coming from free sugars. The Scientific Advisory Committee on Nutrition (SACN) recommendations on sugars Free Sugars is the term used to describe the type of sugars that should be consumed in smaller amounts. This includes all sugars added to food by the manufacturer, cook or consumer plus sugars present in honey, syrups and unsweetened fruit juices but not sugar present in dried or cooked fruit. Under this definition lactose naturally present in milk products and sugars contained within the cellular structure of foods would be excluded. SACN states that these recommendations are designed to minimise risks associated with high free sugars intake and to result in improved management of energy intake, obesity risk reduction and to improve dental health. Reference: British Nutrition Foundation Sugars Factsheet PDF Figure 5.10 The Scientific Advisory Committee on Nutrition (SACN) recommendations on sugars 7

13 CHAPTER 5 MACRONUTRIENTS Activity 6 Dietary patterns in the UK will need to change if the dietary recommendations for carbohydrate are to be met. While most of the population are consuming too many free sugars, intake among adolescents is particularly high. 1 Why is free sugar consumption so high in this age group? 2 Explain how this could impact on the health of adolescents. 3 Suggest ways adolescents could reduce their intake of free sugars. Activity 7 Key words Carbohydrate a macronutrient needed in the body for a range of functions including energy. Sugar a simple carbohydrate that is absorbed quickly by the body and raises blood sugar levels rapidly. Starch a more complex carbohydrate that takes longer to digest and absorb, keeping blood sugar levels constant. 1 Make a collection of food labels and highlight those containing sugars and starches. 2 Make a list of the types of sugar used to sweeten the foods. 3 Suggest ways that the food could be made with less sugar. 4 Suggest ways that the food could contain more starchy carbohydrate. Remember It is important to make healthy choices when shopping for food. Being able to read food labels is one way to achieve this. Free sugars may appear in the ingredients lists as sugar but other words and terms to look for are shown in Figure Cane sugar, honey, brown sugar, dextrose, fructose, sucrose, glucose, maltose, high fructose corn syrup, fruit juice concentrate, corn syrup, molasses, isoglucose, crystalline sucrose, nectars and molasses Figure 5.11 How sugar can appear on a label Ingredients are listed in descending order of weight, so if a type of sugar appears near the beginning of the ingredients list, the product is likely to have more free sugars than one in which sugars are listed at the end. (You can find more information on food labelling in Chapter 12 Factors affecting food choice.) Stretch and challenge 3 1 Look at the ingredients list for a granola and yogurt cereal bar with a total sugar content of 43.9 g per 100 g and record all the types of free sugars in this product. Remember: not all sugars are free sugars. INGREDIENTS: Sugar, palm oil, oats, crisped rice (rice, sugar, salt, barley malt extract), emulsifier E47, raisins, glucose syrup, lactose, pumpkin seeds, dried whole milk, honey, concentrated apple juice. Figure 5.12 Granola and yoghurt cereal bar label 2 Is this cereal bar a healthy choice? Give reasons to support your decision. 8

14 Carbohydrate Review questions Protein 1 Which of the following foods is a source of low biological value protein (LBV)? (1 mark) A Chicken B Milk C Baked beans D Eggs 2 Which of the following foods is a source of high biological value protein (HBV)? (1 mark) A Chicken B Baked beans C Bread D Rice 3 Explain two functions of protein. (4 marks) 4 Describe the difference between dispensable and indispensable amino acids. (4 marks) 5 Explain protein quality and outline why is it so important. (4 marks) 6 Explain the complementary action of proteins. (6 marks) Fat 7 What percentage of dietary energy should come from fat? (1 mark) 8 Identify two differences between saturated and unsaturated fat. (2 marks) 9 Identify two food sources of essential fatty acids (EFAs). (2 marks) 10 List two food sources of saturated fat and two food sources of unsaturated fat. (4 marks) 11 Explain why is it important to include foods rich in omega 3 and omega 6 in the diet. (4 marks) 12 Explain the long-term consequences to health of eating excess fat. (6 marks) Carbohydrate 13 List two sources of starchy carbohydrate. (2 marks) 14 List two sources of sugar. (2 marks) 15 Explain the protein-sparing effect of carbohydrate. (3 marks) 16 Explain why is it important to reduce consumption of free sugars. (4 marks) 17 Explain two functions of carbohydrate. (4 marks) 18 Identify the percentage of dietary energy that should be provided by carbohydrate and explain why meeting this target is so important. (5 marks) Command word focus Explain Set out purposes or reasons Identify Name Practice questions at the end of each chapter to test knowledge and understanding. Key points u Macronutrients are needed by the body in large amounts. u Protein, fat and carbohydrate are macronutrients. u Protein is needed for growth, repair and maintenance of body tissues. u Protein is found in a range of animal, plant and novel foods, such as meat, grains and tofu. u Fat is used for energy and is a valuable source of fat-soluble vitamins and essential fatty acids. u Fat is found in a range of animal and plant foods, such as meat and vegetable oils. u Carbohydrate provides energy and fibre which aids digestion and prevents constipation. u Carbohydrate is found in a range of starchy and sugary foods, such as bread, pasta, table sugar and confectionary. Key points at the end of each chapter summarise the topics covered and support revision 9

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16 CCEA GCSE HOME ECONOMICS FOOD AND NUTRITION This sample chapter is taken from CCEA GCSE Home Economics: Food and Nutrition Student Book. We are working towards endorsement with CCEA for this Student s Book. Fully updated to cover the 2017 CCEA Home Economics: Food and Nutrition GCSE specification, this new edition of the market-leading textbook will guide your students through the content, prepare them for assessment and help you deliver an engaging, cost-effective Home Economics: Food and Nutrition course. u Ensures your students understand even the most challenging topics such as nutrition and consumer law with clear, accessible explanations of all subject content and simple definitions of key words u Helps students apply their understanding of food and nutrition with engaging and cost-effective practical food preparation and cooking activities u Differentiates with stretch and challenge activities to ensure progression and to challenge more able learners u Prepares students for Controlled Assessment with guidance on the Practical Food and Nutrition task u Supports exam preparation with advice on preparing for the written paper and practice exam-style questions throughout AUTHORS Nicola Anderson and Claire Thomson are experienced Home Economics teachers, examiners and authors. First teaching from September 2017 ALSO AVAILABLE Dynamic Learning Dynamic Learning is an online subscription solution that supports teachers and students with high quality content and unique tools. Dynamic Learning incorporates Teaching and Learning resources, Whiteboard and Student etextbook elements that all work together to give you the ultimate classroom and homework resource. Visit CCEA to pre order your class sets or to sign up for your Inspection Copies or einspection Copies. Sign up for a free trial visit: Textbook subject to change due to pending specification accreditation. ISBN