Food Technology. Revision 1 Healthy Eating, Eatwell Plate & Macronutrients

Transcription

1 Food Technology Revision 1 Healthy Eating, Eatwell Plate & Macronutrients

2 Eating for Health Our Diet It is important to choose a variety of foods to ensure that we obtain the range of nutrients, i.e. proteins, carbohydrates, fats, vitamins and minerals, which we need to stay healthy There are guidelines about the amount of nutrients needed by different people. These include dietary reference value (DRV), estimates average requirements (EAR) and reference nutrient intake (RNI)

3 Eatwell Plate The Eatwell Plate shows the types & proportions of the main food groups that are needed for a healthy balanced diet. On the plate you can see how much of your food should come from each group. Fruit & vegetables should make up about one third of the total food per day we eat. A portion is one piece of fruit (apple) or handful of berries (raspberries) You do not need to get the balance right every meal, but need to try to get the balance over a day or each week. Foods & drinks high in fat and/or sugar aren t essential to a healthy diet and shouldn t be eaten often. The Eatwell Plate proportions have just changed (April2016) and we are now advised to eat more than one third fruit and vegetables and slightly less than a third Carbohydtrates

4 Eatwell Plate It is suitable for all except Children under the age of two People under medical care People with special dietary needs

5

6 UK Government Healthy Eating Guidelines 1. Base your meals on starchy staple foods 2. Eat lots of fruit & vegetables 3. Eat more fish, including a portion of oily fish each week 4. Cut down on saturated fat and sugar 5. Eat less salt no more than 6g a day for adults 6. Get active and maintain a healthy weight 7. Drink plenty of water 8. Don t skip breakfast 5 a day campaign Encourages us to eat more fruit & vegetables fresh, frozen, canned and dried Recently this has increased to 7 10 portions per day

7 A healthy diet You should be able to achieve healthy eating by cutting down on fat (especially saturated), salt and sugars & increasing fibre (non-starch polysaccharide or NSP) To help consumers do this, many manufacturers have voluntarily adopted a system of traffic light labelling: Red = amount is high eat occasionally Amber = neither high or low amounts Green = amount is low this is a good choice Some manufacturers use a different system based on Guide Line Daily Amounts (GDA) These labels show the % of sugar, salt, fat & calories in each serving of the product

8 Traffic Light Labelling G.D.A.

9 Maintaining a Healthy Weight By balancing the calories with being physically active, you can maintain a healthy weight. If you eat more calories than your body needs, it gets stored as fat, and you become overweight. To reach a healthy weight you should follow a calorie control diet. If your weight increases to a point where it seriously endangers your health, you may eventually become obese. Being overweight or obese increases the risk of developing Coronary heart disease (CHD) Some cancers Type 2 diabetes High blood pressure, which can lead to strokes Osteoarthritis Being seriously underweight can also lead to health problems

10 Quick Test! 1. Which people should check with their GP whether the Eatwell plate applies to them? 2. Obesity can increase the risk of developing coronary heart disease True or False? 3. How can you maintain a healthy weight? 4. What foods should you cut down on to achieve a healthy diet? 5. Using the traffic light labelling system, a green light means that the food is a good choice to make True or False?

11 Key Words Make sure you understand these words Dietary Reference Values Obesity Guide Line Daily Amounts Healthy weight Eatwell Plate Healthy diet Traffic Light Labelling

12 Healthy Options Manufacturers recognise that many consumers are concerned about healthy eating. They are producing healthy option foods. These foods make claims about Low fat Low salt Low sugar High NSP content We need to know what this actually means

13 Nutrient Definitions Content per 100g Salt Effects of Excess Low salt Less than 0.3g High blood pressure High salt 1.5g or more Coronary heart disease Fat Low fat Less than 3g Overweight High Fat More than 20g Obesity Saturated fat Sugar Low saturated fat Less than 1.5g Raised cholesterol High saturated fat More than 1.5g CHD Low sugar Less than 5g Overweight High sugar More than 15g Obesity Dental decay

14 Fortification Some foods are sold with the claim fortified this is the addition of nutrients to the food Some foods must have some nutrients added in by law e.g. bread must have min amounts of calcium, iron & vitamins; margarine must contain vitamins A & D Other foods such as breakfast cereal do this as a selling point

15 Nutrients Nutrients are divided into 2 categories Macronutrients Which are Protein, Carbohydrate & Fat the body needs larger amounts of these Micronutrients Which are vitamins and minerals the body needs smaller amounts BUT a wide variety Nutrients are substances found in foods. All foods contain a mix of nutrients The body also requires water (found in drinks & food) and fibre found in plant food

16 Protein Needed for growth & repair excess stored as fat During digestion proteins are broken up into amino acids. These are absorbed into the bloodstream & made into new proteins in the body. 20 different amino acids are found in plant & animal proteins. Thousands of amino acids may be joined together to make one type of protein. The body can make 11 of the amino acids from other amino acids. The remaining 9 amino acids have to be obtained from protein in the food we eat these are known as essential amino acids

17 Essential amino acids are found in protein from animal tissue and from soya bean & quinoa these foods have High Biological Value (HBV) Protein from plant sources (other than soya & quinoa) have Low Biological Value (LBV) The body needs a variety of both HBV & LBV Sources of HBV Milk & milk based products (cheese) Eggs Meat Shellfish Fish (3 portions per week) Soya bean & soya bean products (tofu) Quinoa Sources of LBV Quorn Nuts Pulses (peas, beans & lentils) Rice Cereals (oat, wheat) Peanuts

18 Alternative Proteins May be eaten as a substitute for animal protein by- People who do not want to eat food from an animal source because of moral, religious or ethical reasons People who are health conscious People who want a more varied diet TVP textured vegetable protein (made from soya bean) Quorn a mycoprotein related to the mushroom Tivall made from wheat & vegetable protein, similar texture to meat Tofu & Bean Curd made from soya beans Nutritive Value high in protein, low in fat, enriched with vitamins & minerals Properties versatile, can be cooked in different ways, bland, colourless, easy to store & usually cheaper

19 Quick Test 1. State three functions of protein in the diet 2. State the meaning of the term essential amino acids 3. Give the name of one vegetable protein that provides all the essential amino acids 4. State two products that would give a vegan all the essential amino acids 5. State one different source of protein for each of the following target groups (a) toddler (b) lacto-vegetarian (c) elderly person Key Words to remember & understand their meaning Macronutrient amino acid HBV LBV

20 FATS Provides the body with energy, keeps it warm, protects vital organs (kidneys) & contains fat soluble vitamins A & D Fats are solid at room temperature where oils are liquid. Fat can come from animal & plants. All fats are high in calories, fat intake should be no more than 35% of our energy intake, excess is stored as body fat Visible fats seen on meat or as butter etc. Invisible fat appear in ready meals, biscuits, cakes, burgers etc. Saturated fats solid at room temp., mainly from animals too much leads to high blood cholesterol, CHD, diabetes & obesity Polyunsaturated fats are soft & oily at room temp, considered heathier option Essential fatty acids (EFAs) cannot be made by the body. Omega 3 found in oily fish, seeds, green leafy veg helps protect heart Omega 6 veg, fruit, grains, chicken helps lower blood cholesterol

21 Functions frying (chips), enriching (sauces), shortening (pastry), emulsifying (mayonnaise), colour (pastry), creaming (cakes) Hydrogenated fat - hydrogen is bubbled through some oils to improve flavour & shelf life margarine, spreads, used in manufactured cakes, biscuits etc is as harmful as saturated fats. Sources Plant fruits (avocado), nuts, pulses & seeds Animal meat (& their products lard, suet), dairy (milk, cheese) & oily fish Saturated Fats Meat pies, sausages, hard cheese, coconut & palm oil, butter, ghee, lard, cream Unsaturated Fats Oily fish, avocados, nuts, seeds, sunflower & corn oil, vegetable oil, soya beans

22 Carbohydrates Provides the body with ENERGY for physical activity (walking) and to maintain bodily functions (breathing), it also provides us with fibre to help with digestion and sweetens/flavours our food. Excess is stored as fat which leads to overweight/obesity Types of Carbohydrates STARCH SUGAR NSP Polysaccharides Monosaccharides Non starch (complex) (simple sugars) polysaccharides pasta, rice honey, fruit Oats, bananas, beans Disaccharides Double sugars (Lactose & Sucrose) Milk, caster sugar

23 Sugars provide instant energy. Starches have to be digested into sugars before energy can be released & therefore convert to energy more slowly. Sugar causes tooth decay therefore important to brush teeth after eating sugary foods The only function of sugar is energy. It does not contain any other nutrients

24 Dietary Fibre - NSP Dietary fibre is the non-digestible cellulose found in plant foods. It cannot be digested so it passes straight through the digestive system, absorbing moisture and providing bulk. We should be eating approx. 18g of fibre every day. Functions It holds water & keeps the faeces soft & bulky It helps push other foods through the system & to clean the intestine of bacteria It helps prevent bowel disorders, including constipation & bowel cancer It can help people control their weight because high fibre foods are filling High fibre diets are linked to lower blood cholesterol

25 Quick Test 1. Why do marathon runners eat starchy foods? 2. Give three functions of carbohydrates in the diet 3. Name two health conditions which may be caused by an intake of low dietary fibre 4. List two foods which are a good source of dietary fibre

26