Introduction to nutrition

Transcription

1 Introduction to nutrition GCSE/Standard Grade Presented by: Sarah Schenker Overview What is nutrition? Why is what we eat important? Why do we eat? What should we be saying? Nutrition Scientist 14 th September 2010 Georgine Leung Nutrition Scientist Understanding nutrition Draws on understanding from many different disciplines, such as: physiology, anatomy and pathology; food chemistry; sociology and psychology. 1

2 History of nutrition During the 20 th century, the role of nutrients in health and disease was discovered. Today it is clear that diet affects risk of chronic diseases such as heart disease and cancer. Nutrition is also important for good health physical and mental wellbeing. The global perspective In less developed regions, famine and chronic undernutrition remain a constant threat. In the UK, there are major inequalities in health linked to poor diet. Developing countries are also seeing a rise in diet-related diseases as they start to adopt the western diet. 2

3 Nutrition in the media Have you seen any diet or nutrition stories in the media this week? 3

4 The need for a healthy diet To provide sufficient energy and nutrients to maintain normal physiological functions and grow and replacement of body tissues. To offer the best protection against the risk of disease. Why is what we eat important? Overweight and obesity. Cardiovascular disease. Diabetes. Cancer. Bone and joint health. Nutrient deficiencies. 4

5 8 tips for eating well 1. Base your meals on starchy foods. 2. Eat lots of fruit and veg. 3. Eat more fish. 4. Cut down on saturated fat and sugar. 5. Try to eat less salt not more than 6g a day. 6. Get active and try to be a healthy weight. 7. Drink plenty of water. 8. Do not skip breakfast. 5

6 Dietary Reference Values (DRVs) Children Adolescents Adults Older adults Energy Energy is fundamental for survival. Energy is derived from the metabolism of carbohydrate, fat and protein in food kj per gram Carbohydrate Protein Alcohol Fat Energy is also derived from alcohol. 6

7 Energy Estimated average requirements (EARs) for energy have been set for different population groups. Men 10,600 kj per day (2,550 kcal) Women 8,100 kj per day (1,940 kcal) Currently 66% of men 53% of women have a BMI of over 25. Macronutrients Carbohydrate is rapidly broken down to glucose and is the most readily available source of energy. Fat is a concentrated source of energy, provides essential fatty acids and carries fat soluble vitamins. Protein provides amino acids essential for growth and repair of body tissues, can be used as a source of energy when necessary. 7

8 Macronutrients Recommended that about 50% of total energy should come from carbohydrate. Current carbohydrate intake 47% Recommended that no more than 35% of energy from total fat. This leaves 15% energy from protein. Current total fat intake 35% Current protein intake 18% Vitamins, minerals and trace elements Many different substances are required by the body for enzyme systems, transport mechanisms, structural synthesis and regulatory processes. Most are only needed in minute quantities and they do not provide energy. However, they are essential for maintaining health or even life. 8

9 Dietary fibre (NSP) Dietary fibre (NSP) is not absorbed by the body. It is needed to maintain normal bowel function. It also increases satiety, helps to lower blood cholesterol levels and boost immunity. Further effects remain to be evaluated. Dietary fibre (NSP) Recommended that we eat 18g of dietary fibre (NSP) per day. Current dietary fibre intake 14 g per day This is linked to fruit and vegetable intakes. Recommended that we eat at least 5 portions per day. Current fruit and vegetable intake 2.8 portions per day 9

10 Water Water is essential for life, survival time without water can be a matter of days or hours. Dehydration can lead to thirst, headaches, loss of concentration and some poor health outcomes, such as constipation. Water is provided by both food and drink. Water What is the average daily requirement for water? a) 1 litre b) 1.2 litres c) 1.5 litres d) 2 litres 10

11 Recommendation Why? F&V At least 5x80g/d risk some cancers, CVD and other chronic diseases Oily fish At least 1x140g/wk risk CVD NMES < 11% en (~60g/d) risk dental caries Fat Average 35% en risk CVD and energy density of diets Saturates Average 11% en risk CVD and energy density of diets NSP Average 18g/d To improve GI health Alcohol Salt Vitamins and minerals Physical activity No more than Men: 3-4 units/d Women: 2-3 units/d Average 6g/d (11 years or above) DRVs At least 60 minutes each day Minimise risk of liver disease, CVD, cancers, injury from accidents and violence risk hypertension and CVD To promote optimum health and prevent deficiency risk CVD, DM, some cancers and body weight Body weight BMI kg/m2 risk some cancers, CVD and other chronic diseases Salt It is recommended that we eat no more than 6 g of salt per day. Question: Do you think we are meeting this? 11

12 What should we be saying? More fruit and vegetables, pulses, wholegrain foods. More milk and dairy foods. More oily fish. Less foods high in saturated fat and added sugars. Less salt. More active. For further information, go to: BNF is grateful for financial support from the Agricultural and Horticultural Development Board to enable us to develop these eseminars. 12