1 Chapter 1 Introduction to Nutrition

2 Factors Influencing What You Eat Flavor Taste Smell Appearance Texture Temperature Other Aspects of Food Cost Convenience Availability Familiarity Nutrition

3 The most important consideration when choosing something to eat is flavor. The most important consideration when choosing something to eat is flavor. (Courtesy of PhotoDisc/Getty Images)

4 Factors Influencing What You Eat Demographics Age Gender Educational level Income

5 Factors Influencing What You Eat Culture and Religion Traditional foods Special events/celebrations Religious foods/practices

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

7 Factors Influencing What You Eat Social and Emotional Influences Social status Peer pressure Emotional status Food associations

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

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

10 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.

11 Nutrients are: Nourishing substances in food that provide energy and promote the growth and maintenance of your body.

12 Kilocalories A measure of the energy in food. 1 kilocalorie raises the temperature of 1 kilogram of water 1 degree Celsius. Also called a Calorie. Abbreviated as kcalorie or kcal. When you hear “calorie,” it is really a kilocalorie.

13 The number of kilocalories you need is based on: Basal metabolism (about 2/3 of total energy needs for individuals who are not very active) Physical activity Thermic effect or specific dynamic action of foods (5 to 10% of total energy needs)

14 BMR depends on factors such as: Gender Age Growth Height Temperature Fever and stress Exercise Smoking and caffeine Sleep

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

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

17 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.

18 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.

19 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. 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.

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

21 Functions of Nutrients NutrientsProvide EnergyPromote Growth and Maintenance Regulate Body Processes Carbohydrates X Lipids X X X Proteins X X X Vitamins X X Minerals X X Water X X

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

23 Carbohydrates4 kcal/gram Lipids9 kcal/gram Protein4 kcal/gram

24 More Vocabulary Micronutrients Macronutrients Organic nutrients Inorganic nutrients Carbohydrates Lipids Proteins Vitamins Minerals Water

25 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.

26 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.

27 Nutrient Density Comparison: % DRI intakes for selected nutrients.

28 Characteristics of A Nutritious Diet Adequate Balanced Moderate Varied

29 Dietary Reference Intakes (DRI) Recommended Dietary Allowance (RDA) Intake value sufficient to meet nutrient requirements of 97-98% of all healthy individuals in a group. Adequate Intake (AI) Intake value used when a RDA cannot be based on an EAR because there’s not enough scientific data. Tolerable Upper Intake Level (UL) Maximum intake level above which toxicity would increase. Estimated Average Requirement (EAR) Intake value estimated to meet requirement of half the healthy individuals in a group.

30 Dietary Reference Intakes Estimated Energy Requirement (EER) The dietary energy intake measured in kcalories that is needed to maintain energy balance in a healthy adult. Acceptable Macronutrient Distribution Ranges (AMDR) A range of intakes for a particular nutrient that is associated with reduced risk of chronic disease while providing adequate intake. Adults: 45-65% of kcal from carbohydrates, 20-35% from fat, and 10 to 35% from protein.

31 Dietary Reference Intakes RDA and AI – useful in planning diets for individuals EAR - useful in planning diets for groups

32 Digestion, Absorption, & Metabolism Digestion: Process by which food is broken down into its components in the gastrointestinal tract with the help of digestive enzymes. Absorption: The passage of digested nutrients through the walls of the intestines or stomach into the blood or lymph, where they are transported to the cells. Metabolism: All the chemical processes by which nutrients are used to support life, includes anabolism and catabolism.

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34 Food Basics 1. Whole foods 2. Fresh foods 3. Organic foods 4. Processed foods 5. Enriched foods 6. Fortified foods

35 Organic Foods Organic food is produced without using most: Conventional pesticides Petroleum-based fertilizers or sewage sludge- based fertilizers Bioengineering Ionizing radiation (irradiation) Organic farms must be inspected annually. All organically-raised animals may not be given hormones or antibiotics, and must have access to pasture.

36 Labeling of Organic Foods Courtesy of USDA

37 Clip art images may not be saved or downloaded and are only to be used for viewing purposes. Copyright ©2007 John Wiley & Sons, Inc.