Food TechnologySpecial Diets These icons indicate that teacher’s notes or useful web addresses are available in the Notes Page. This icon indicates the slide contains activities created in Flash. These activities are not editable. This icon indicates that an activity contains sound. For more detailed instructions, see the Getting Started presentation. 1 of 22 © Boardworks Ltd 2005
Learning objectives • To understand that our dietary needs change through life. • To understand that people follow different diets for a variety of reasons. Learning objectives 2 of 22 © Boardworks Ltd 2005
Getting the right amounts of nutrients We should all be following The Balance of Good Health recommendations published by the government in order to get the right quantities and proportions of nutrients our bodies need. Different people require different amounts of nutrients.
A teenager’s diet • Teenagers require more energy food than adults because they are growing and often very active. • Foods which are high in calcium and protein should be eaten to help bone and muscle growth; foods which are high in other minerals and vitamins should also be eaten. • Teenage girls need more iron. • Grazing on snacks which are high in sugar and fat should be avoided.
What is food intolerance? • Some people, such as diabetics and coeliacs, have to restrict their diet because their bodies react badly to certain types of food. This is called food intolerance. • Other people are allergic to some foods – most commonly to milk, eggs, nuts, fish, shellfish, soya, wheat or gluten. In an allergic reation, the body thinks the food is not safe and releases chemicals (histamines) to deal with it. In a severe allergic reaction, the body goes into shock and in rare cases the person can die. Labelling foodsclearly is very important to people with food intolerance or allergies.
What is coeliac disease? As many as 1 in 300 people in the UK have coeliac disease, which is an intolerance to gluten. Gluten is found in cereals such as wheat, barley, rye and oats. If coeliacs eat gluten, they damage their small intestine making absorption of nutrients difficult. In the long term, this leads to weight loss and malnutrition. Maize (corn) is a cereal which is gluten-free and can be eaten by coeliacs; some coeliacs might also eat oats as the gluten content in oats is very low. Since so many food products are made from wheat, people who are diagnosed with coeliac disease need to think about their diet very carefully. They should also check food labels carefully for the ‘hidden’ wheat products.
Cereal or starch flours manioc (from cassava) quinoa potato To make gluten-free products, cereals other than wheat, barley, rye and oats must be used. These cereal or starch flours can be used for cakes, biscuits, pastry and bread. rice sorghum soya buckwheat tapioca millet maize (corn) nut (especially almond)
Making gluten-free products Food manufacturers experiment with different flours when making gluten-free products. A fruit cake might contain a mixture of almond, manioc, buckwheat and maize flour. Bread is the most difficult gluten-free product to make since it is the gluten in wheat which creates the texture and structure of bread as it is stretched during kneading. Doves Farm company, however, does make a gluten-free brown bread flour which contains rice, potato and tapioca flours plus natural fibre and gums for baking strength.
Vegetarian diets • A vegetarian diet consists of grains, pulses, nuts, seeds, vegetables and fruits and in many cases, also dairy products and eggs. Vegetarians do not eat meat, poultry, game, fish or shell fish. • People become vegetarian for ethical, moral and health reasons. The number of vegetarians has nearly doubled to at least 5% of the UK population in the last ten years. • One-third of the population eats meat only occasionally and two-thirds of the population eats some meatless meals. • There are different types of vegetarians: lacto-ovo-vegetarian, lacto-vegetarian, vegan and semi- or demi-vegetarian. • Vegetarians and vegans need to be careful that they get all the nutrients they need as whole food groups are missing from their diets; tofu and quorn are good meat (protein) substitutes.
Sports nutrition Some people need to be particularly careful with their diets on account of their jobs or the activities they do. Sportsmen and sportswomen take their diet very seriously, because it can help to improve their performance. • Physical exercise uses up energy and it is important to eat the right foods to provide an energy store. Starches release their energy more slowly than sugars and are good for long distance. • Fluids are also very important to avoid becoming dehydrated. Exactly what the best diet is will depend on the type of sport and professional sportsmen and women will be helped to find the most appropriate diet for their particular sport by a trainer.
Key points • If we eat a balanced diet, most of us will get all the nutrients we need. • Our dietary needs change through life as we grow older and our activities change. They are not always the same for men and women. • Some people restrict their diet on account of their religious beliefs. • Some people need to avoid certain foods for medical reasons. • Some people change their diet due to personal needs. • If a food group is excluded from our diet, we must ensure that the missing nutrients are obtained from alternative sources. Key points 22 of 22 © Boardworks Ltd 2005