Chapter 1

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

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

Factors Influencing What You Eat

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

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

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

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

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

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

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

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

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

• Health
– Health status
– Desire to improve health/appearance
– Nutrition knowledge and attitudes
15

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
17

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

• 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

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

• 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

60%

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

• Example: 150# body
– Water = 90#
– Fat = 20 -45#
– Carbohydrate, Protein, Major Minerals
= 15 -40#
– Vitamin, Minor Minerals = < 1#

• Energy defined
– Capacity to do work
– 5 h
• Nutrient defined
– Growth
– Maintenance

Carbohydrates
Lipids
Protein
4 kcal/gram
9 kcal/gram
4 kcal/gram p. 12
17. a 27

Nutrients Provide
Energy
Promote
Growth
Maintenance
Regulate
Body
Processes
Carbohydrates
Lipids
Proteins
Vitamins
Minerals
Water
X
X
X
X
X
X
X
X
X
X
X
X
X
28

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

• Inorganic nutrients
– Minerals -Water
• Organic nutrients
– Carbohydrates -Lipids
– Proteins -Vitamins

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

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.
33

• Carbohydrates • Vitamins
• Lipids (fats)
• Proteins
• Minerals
• Water
35

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

• 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.

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

• 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

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

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

• 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

• Which food item has the greatest nutrient density?
• “NuVal”?

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

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

Characteristics of A Nutritious Diet
•
•
•
•
p. 16
49

• A dequacy-amounts sufficient to maintain health
• B alance-foods proportionate to each other and body
’ s needs
• C ontrol-Kcalorie (energy)-food energy intake management
• Moderation
: Enough but not too much

• D ensity: Caloric/Nutrient
– Empty-kilocalorie foods
– Nutrient dense foods
• VARIETY!
– Eating a wide selection
– Whole foods

• Dietary Reference Intake: a set of values that serve as standards for nutrient intakes for healthy persons.
52

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.
53

Dietary Reference Intakes
• 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.
• 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
– 25-35 % from fat
– 10-36% from protein p. 17
54

Dietary Reference Intakes
• RDA and AI – useful in planning diets for individuals
• EAR - useful in planning diets for groups
55

DRI

DRI

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.
59

• Digestibility: The amount of a food or nutrient that is available for absorption after digestion.
• NOT a set of symptoms associated with eating or digestion.
– Reflux symptoms
• “After taste”
• Belching, burping
• “Heartburn”
• Regurgitation
– Intestinal gas formation
– Upset stomach, “indigestion”
– Nausea, vomiting, diarrhea
60

61

• Using the last two slides as a guide, write down what would happen to a piece of pizza in each part of the body.
• Work with your group of colleagues if you would like.
• Let your instructor know when you are done.

1. Whole foods – fresh, unprocessed
2. Fresh foods – raw, no preservatives
3. Processed foods – procedure applied:
• Canning, freezing, dehydrating, milling
4. Enriched foods – nutrients replaced
5. Fortified foods – nutrients added p. 26-29
67

• Textured vegetable protein
• Imitation foods (cheese, milk)
• Food substitutes (egg)

• Functional foods
• Provide health benefits beyond their nutrient contributions
• Ex. Whole foods, fortified foods, modified foods
(engineered, designer)
– Calcium fortified orange juice
– Margarine containing plant sterols
– 4-n

• Organic food is produced without using most:
– Conventional pesticides
– Petroleum-based fertilizers or sewage sludgebased 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.
70

Courtesy of USDA
71

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

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