Introduction to Nutrition

1. Introduction to Nutrition Chapter 1

2. Objectives • After reading Chapter 1, class activities and discussion you will be able to • Define frequently used terms • Identify factors affecting food choices • Discuss six major nutrient classes • Describe Dietary Reference Intakes • Describe ABCD’s of diet planning principles

3. Objectives • After reading Chapter 1, class activities and discussion you will be able to: • Distinguish energy density of foods • Distinguish food’s nutrient density • Identify the energy value of carbohydrate, protein, and fat • Calculate the energy available from foods

4. Food Choices

5. Factors Influencing What You Eat Why do we choose the food we eat?

6. Factors Influencing What You Eat The most important consideration when choosing something to eat is flavor! 6

7. Factors Influencing What You Eat Flavor Taste Smell Appearance Temperature Texture Other Factors Cost Convenience Availability Familiarity Nutritional Value 7

8. How Taste Influences What You Eat • Flavor of food is recognized by the • Sense of taste • Sense of Smell • Flavorous chemicals must be dissolved in water before they can be tasted • Dry mouth prevents adequate tasting

9. How Taste Influences What You Eat • 10,000 taste buds; 4 main types: • Sweet, Sour, Salty, Bitter • Umami, Piquant • 50-150 receptor cells per taste bud • 1-2 weeks cell life • Each receptor cell reflects all flavors but more sensitive to one

10. How Taste Influences What You Eat • Origins of different tastes: • Sweet = Saccharin of sugar • Sour = Acid • Salty = Salt, sodium chloride • Bitter = Alkaloids • Umami, Piquant

11. Factors Influencing What You Eat • Demographics • Age • Gender • Educational level • Income

12. Factors Influencing What You Eat • Social and Emotional Influences • Social status • Peer pressure • Emotional status • Food associations

13. Factors Influencing What You Eat • Food Industry and the Media • Food industry • Food advertising • Food portrayal in media • Reporting of nutrition/health studies

14. Factors Influencing What You Eat • Environmental Concerns • Use of synthetic fertilizers and pesticides • Wastefulness of fattening up livestock/poultry

15. Factors Influencing What You Eat Health Health status Desire to improve health/appearance Nutrition knowledge and attitudes 15

16. What is Nutrition?

17. What is Nutrition? Nutrition is a science that: • studies nutrients and other substances in foods and in the body and how these nutrients relate to health and disease, and • explores why you choose particular foods and the type of diet you eat. • science of foods and nutrients • 1 q. p. 9

18. Nutrients Nourishing substances in food that provide energy and promote the growth and maintenance of your body. 6. i p. 9

19. Nutrients • Nutrient composition of foods and the human body are similar • Nutrient composition of foods • Six classes of nutrients • Nonnutrients • Example: Phytochemicals • 7. j • p. 222

20. Foods • Derived from plant or animal sources • Provide energy and nutrients • Used by the body for maintenance, growth, and repair • 2 p

21. Diet • The foods one consumes affects • The quality of life now • The risk of chronic diseases later • UC San Francisco study-Aug 2010 • 3258 subjects 18-30 y.o. • Studied for 20 years • 5 ½ x more likely to develop CHD • 3 o p. 10

22. Body Composition 60%

23. Nutrients in the Body • Nutrient composition of the body • Water = 60% • Fat = 13-31% • Male = 13 -21% • Female = 23 -31% • Carbohydrate, Protein, Vitamins, Minerals, Other = 9 – 27%

24. Nutrients in the Body • Example: 150# body • Water = 90# • Fat = 20 -45# • Carbohydrate, Protein, Major Minerals = 15 -40# • Vitamin, Minor Minerals = < 1#

25. Review Nutrients e Food e Diet

26. More About Nutrients • Energy defined • Capacity to do work • 5 h • Nutrient defined • Growth • Maintenance

27. Energy-Yielding Nutrients Carbohydrates 4 kcal/gram Lipids 9 kcal/gram Protein 4 kcal/gram p. 12 17. a 27

28. Functions of Nutrients 28

29. More About Nutrients • Chemical composition of nutrients • Inorganic vs. Organic nutrients • Inorganic = contain NO carbon • Organic = contain carbon • Organic literally meaning “alive” • 9 l • 10 m

30. More About Nutrients • Inorganic nutrients • Minerals -Water • Organic nutrients • Carbohydrates -Lipids • Proteins -Vitamins

31. The Nutrients

32. Nutrients • Essential nutrients (approx. 40) • 11 f • Macronutrients -12. g • Carbohydrates • Proteins • Fats • Micronutrients • Vitamins • Minerals

33. Essential Nutrients Nutrients that either cannot be made in the body or cannot be made in the quantities needed by the body; therefore, we must obtain them through food. EXAMPLES Glucose, vitamins, minerals, water, some lipids, and some parts of protein.

34. Six Classes of Nutrients

35. Classes of Nutrients - Overview Carbohydrates Lipids (fats) Proteins Vitamins Minerals Water 35

36. Carbohydrates A large class of nutrients, including: Sugars Starch Fibers that function as the body’s primary source of energy. 36

37. Lipids A group of fatty substances, including triglycerides and cholesterol, that are not soluble in water and provide a rich source of energy and structure to cells.

38. Protein Major structural parts of the body’s cells that are made of nitrogen-containing amino acids assembled in chains. Particularly rich in animal foods. Present in many plant foods. 38

39. Vitamins and Minerals Vitamins: Noncaloric, organic nutrients found in a wide variety of foods that are essential to: regulate body processes. maintain the body. allow growth and reproduction. 15. c Minerals: Noncaloric, inorganic nutrients found in a wide variety of foods that are essential to: regulate body processes. maintain the body. allow growth and reproduction. 16. b 39

40. Water Inorganic nutrient that plays a vital role in all bodily processes and makes up just over half of the body’s weight. 40

41. Food Facts Most foods provide a mix of nutrients. Food contains more than just nutrients – food may contain colorings, flavorings, phytochemicals, caffeine, and other substances. 41

42. Nutrient Density

43. Nutrient Density All foods were not created equal in terms of the kcalories and nutrients they provide. Nutrient density: A measure of the nutrients provided in a food per kcalorie of the food. Empty-kcalorie foods: Foods that provide few/no nutrients for the number of kcalories they contain. 8. k p. 13-14 43

44. Nutrient Density Which food item has the greatest nutrient density? “NuVal”?

45. Nutrient Density Comparison: % DRI intakes for selected nutrients. p. 14 45

46. Energy Density Energy Density A measure of the energy a food provides relative to the amount of food (kcal per gram) “empty calories” 14. d

47. Energy Density

48. Nutritious Diet

49. Characteristics of A Nutritious Diet Adequate Balanced Moderate Varied p. 16 49

50. Diet Planning Principles Adequacy-amounts sufficient to maintain health Balance-foods proportionate to each other and body’s needs Control-Kcalorie (energy)-food energy intake management Moderation: Enough but not too much