Science of Food & Nutrients

1. Science of Food & Nutrients Dr Asna Urooj Associate Professor Dept of Food Science & Nutrition University of Mysore Mysore

2. What is nutrition?? Nutrition – science of food, the nutrients & other subs.. Their action, interaction & balance in relation to health & disease. Process by which organisms.. Ingest, digest, absorb, transport, utilize & excrete. Health - state of complete physical, mental & social well being . Not merely the absence of disease / infirmity.

3. Nutritional Status condition of health of the individual as influenced by utilization of nutrients. determined → medical, dietary history, physical examination laboratory tests Malnutrition pathological state .. Relative or absolute deficiency or x’s of one or more essential nutrients – 4 forms Under nutrition Over nutrition Imbalance Specific deficiency

4. Science of Food and Nutrients Science of food – study of chemistry, physics, biology & economics of food & its production. - Involves agricultural & veterinary science. Amount & type of food – Environmental factors Differences in food – storage, preparation distribution, Differences between people – sensory, personal, cultural, social and medical.

5. Nutrients - chemicals in food needed to maintain life. Substances - may include nonessential nutrients, additives, toxicants contaminants. Essential nutrients - 46. Provided by the food we eat. Carbohydrates Proteins Fats/lipids Vitamins Minerals

6. Basics Nutrition & wellness - Nutritional perspective. Dr. Asna Urooj. • For every physical activity, the body requires energy and the amount depends on the duration and type of activity • Energy demand exercise. • Metabolic systems supply energy Aerobic & Anaerobic. • Energy is obtained ---- body stores or the food • Glycogen -- main source of fuel used by the muscles -- aerobic and anaerobic exercise.

7. How FOOD Becomes YOU Nutrition & wellness - Nutritional perspective. Dr. Asna Urooj. • Defn of Nutrition – several processes Ingestion & digestion | Absorption | Transportation | Utilization | Excretion

8. Energy is used in 3 ways Nutrition & wellness - Nutritional perspective. Dr. Asna Urooj. 1 –Digesting food 10% 2 - Physical activity 25% 3 - Basal Metabolic rate ( BMR) 65% BMR – all functions that support life 24 hours Can’t change the percent But You can change your energy demand

9. Facts about Body weight SCEINCE OF FOOD & NUTRIENTS . Dr. Asna Urooj. Body is composed – water, fat, muscle, bone,minerals • Composition varies with age • Controlled by hormones, diet, exercise, stress etc. Body Mass Index = wt (kg) / ht 2 (m) • Ideal range = 19 – 23 for Indians • Over weight BMI is > 23 – 26, • obese >27 • Waist to Hip ratio (WHR) – Central obesity • Ideal = 0.8

10. Body Mass Index indicator of health risk SCEINCE OF NUTRIENTS Dr. Asna Urooj. • eg – 75 kg / 1.7 X 1.7 m = 26 BMI class Presumptive diagnosis < 16.0-18.5 Chronic energy deficiency 18.5 - 20 Low weight – normal 20 - 23 Normal 23 - 27 Obese grade I > 27 Obese grade II

12. NUTRIENT SUPPLY FOOD Amount Energy Protein CHO Fat g/ml Kcals g g g • Cereals 100 350 6-12 60-70 1-2 • Pulses 100 340 18-25 60 1-5 • Milk 100 65 3-5 8 4-6 • Vegetables 100 35- 55 1-2 8-15 - • Oils / fats 20 180 - - 20 • Fruits 100 30-55 1-1.5 10-15 - • Sugar 20 80 - 20 - • Meat 100 80-140 12-22 - 3-13

13. Three types of fats SATURATED FATS ------- BAD Carbon chains with hydrogen bonds Meat, Butter, coconut, milk chocolate, creams, Ghee UNSATURATED FATS ----- GOOD carbon chains with one or more double bonds Monounsaturated : olive oil, nut oils Polyunsaturated : corn oil, vegetable oils, soy etc. TRANS FATS -- BAD Manufactured fats. Liquid  Solid (hydrogenation)

14. Facts about fats Source of energy, 1g = 9kcal, Source of Essential Fatty Acids. Carrier for fat sol vit A, D,E, K Palatability Satiety value Invisible & visible fat Cholesterol – only foods of animal origin

15. Carbohydrates: more than sugar Starches, sugars and fiber. Simple sugars – fructose, glucose, lactose Sweetness varies Complex carbohydrates – starch, glycogen, cellulose, pectins. Most carbs in our diet come from Plant foods Starches & sugars – 4 kcal per gram

16. Carbohydrates - importance Provide energy. Stored as glycogen in the body. Protein sparing Antiketogenic action Bulk – by fiber in diet specialized functions- structural “scaffolding” of cells, signal transduction, ribose – DNA & RNA,

17. Food sources of carbohydrates • Sugars honey, fruits, berries, cane sugar, jaggery, jams, soft drinks, milk, confectionary etc. • Starches cereals, pulses, potatoes, vegetables, animal food (liver, oysters, crab) • Fiber whole grams, Unrefined cereals, pulses,vegetables, fruits, nuts

18. Research information • Similar content – cereals, pulses • Differ in digestibility – food source- cereal, pulse • Food form – influences digestibility • Method of cooking- steaming, pr cooking, boiling, baking Processing influences digestibility & glycemic response

19. Facts About Proteins • Needed for survival, growth, maintenance, enzymes, hormones • Building blocks amino acids – e.a.a & n.e.a.a • “ 2 Q’s ” - Quantity & quality matters – nutritional value of protein foods • Food processing – insignificant effect • Digestibility (%) varies among sources Egg > soy, milk, corn * > wheat>milk> rice> corn,beans, milk *> corn > corn, beans ( *taken together)

20. Proteins – facts • Protein-rich foods are often high in fat • Expensive eg., dairy foods, meat • Foods differ in amino acid composition • Differ in biological value • Protein needs differ in different groups • Extra needs – growth, pregnancy, lactation, surgery, injury, burns, recovery from mal-nutrition

21. Knowledge of foods with High BV • People on veg diets, starvation ( limited food sources) Fruitarians Vegans Lactovegetarians Lacto-ovogetarians Semi- vegetarians • People on wt-reducing diets • Poor quality protein improved – combined with right foods. Eg: cereals + legumes, bread+ cheese

22. Proteins • Nitrogen balance- +, -, equilibrium. Protein status of a person • Heat no harmful effect • High protein diets – health consequences High fat intake – body fat Calcium loss Dehydration, fluid imbalance Gout

23. Balanced Diet Contains different types of foods in such quantities & proportions so that the need for various nutrients is adequately met - provision for extra nutrients – to withstand short duration of low intake - to calculate – know Recommended Dietary Allowances [ RDA] – ICMR - Tables of Food Composition

24. RDA – influenced by • AGE, GENDER • PHYSIOLOGICAL STATE • ACTIVITY • DIETARY FACTORS – Bioavailability _ Inter relationship b/w nutrients

25. Who are likely to have nutrition problems • Elderly • Poor • Large size families • Pregnant women • Children • People in isolated communities

26. Deficiencies seen • Malnutrition – prot-energy in children • Anemia – children, preg &lact women, elderly • Vitamin A – children • Iodine [ IDD] – newborn, cren, Adults

27. HEALTH OR DISEASE NUTRITION DIET ENVIRONMENT EXTERNAL INTERNAL Food Patterns - Family - Area - Culture Biological set points Genetic Ecological Technological Life events Fetal development Psychological Sleep Body frame Organ function Economical Organ system Individual differences Gender Age Activity Body size Behavior DETERMINANTS OF HEALTH

28. BASIS FOR GOOD HEALTH • Carbohydrates- Sources/Form • Fat - Saturated vs. unsaturated • Protein - Animal vs. vegetable • Micronutrients- Vitamins, Minerals • Energy - Restricted only if intake>expenditure • Other factors - Food processing Meal timings Portion size Nutrient density Stress

29. BREAKFAST • Should be main meal of the day • Up to 1/3 of RDA may be supplied • Should be eaten in mid-morning rather than later • Should be eaten within 45 min. of waking • Thyroid activity is maximum and insulin activity is low – better energy utilization of food, hence • People trying to lose weight should not skip breakfast • Should contain: • Carbohydrates – minimum of 50g • Stimulate/initiate insulin action • Neurotransmitters – serotonin & catecholamine • Protein – 12-15g • Sustains insulin action • Promotes positive mood

30. PHYSICAL ACTIVITY • Regular physical activity can reduce your risk of: • Depression and anxiety • Dying prematurely • Developing: • High blood pressure • Diabetes • Osteoporosis • Colon cancer • Regular physical activity can help you: • Feel better • Control weight • Have more energy • Increase your sense of well-being • Reduce stress • Build healthy bones, muscles and joints • Become stronger • Live longer

31. I tried all the fitness fads, but my dietitian was right all along – walking is the best exercise PHYSICAL ACTIVITY • High impact exercises – no effect on fat • Low impact exercises – regulate fat loss • Aerobic exercise improves O2 capacity of the cells • Controls hypertension, cholesterol • Stimulates release of certain chemicals- • Endorphin, Enkephaline • Natural pain killers,  anxiety • Interleukin, Interferons • Strengthen defense mechanism AIM AT FAT LOSS, NOT WEIGHT LOSS

32. STRESS • Can affect onset of disease as well as progression & recovery from disease • Under stress, Adrenaline is released – burns fat for release of glucose for energy. • Cortisol released for utilization of left-over released energy – favours redistribution of fat to abdomen • Higher Waist-to-Hip ratio (gluteal femoral obesity) - An adaptation to stress • Stress has been linked to: • Cancer Alcohol and substance abuse • Diabetes Cardiovascular disease • Breakdown in the immune system

33. FOOD PYRAMID FOR HEALTHY EATING

34. General Dietary Recommendations • Consume high-carbohydrate & fibre, low to normal fat and moderately high protein diet. • Regular meal timings with breakfast eaten within 45 min. of waking. • Inclusion of pulses, especially in the breakfast. • Consumption of a mixed cereal diet with green leafy vegetables at least 3-4 times a week. • Consumption of fruits should be along with meals if diabetic. • If overweight/obese, exercise along with dieting to reduce body weight. • Even if one has normal body weight, exercise to maintain weight.

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