introduction to nutrition chapter 1- week 1. objectives after reading chapter 1, class activities...

Introduction Introduction to Nutritionto Nutrition

Chapter 1- Chapter 1- Week 1Week 1

ObjectivesObjectives

• After reading Chapter 1, class activities and discussion you will be able to:

– Identify factors affecting food choices– Define frequently used nutrition terms– Discuss six major nutrient classes– Describe Dietary Reference Intakes– Describe ABCD’s of diet planning principles

ObjectivesObjectives

• 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– Discuss principles of food digestion and

absorption– Define various types of foods

Food ChoicesFood Choices

Factors Influencing What You EatFactors Influencing What You Eat

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• Flavor!Flavor!

How Flavor Influences What You How Flavor Influences What You EatEato Flavor of food

combineso Sense of tasteo Sense of Smell- Aroma

o Flavorous chemicals dissolve in saliva

o Dry mouth inhibits

How Taste Influences What You How Taste Influences What You EatEat

o 10,000 taste buds; 4 main types:o Sweet, Sour, Salty, Bittero Umami, Piquant, Savory

o 50-150 receptor cells per taste bud

o 1-2 weeks cell life


• Cost• Convenience• Availability• Income

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• Social and Emotional Influences– Social status– Peer pressure– Emotional status– Food associations

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• Food Industry and the Media– Food industry

– Food advertising– Food portrayal in

media– Reporting of

nutrition/health studies

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• Environmental Concerns– Use of synthetic fertilizers

and pesticides– Production techniques

13

Factors Influencing What You Eat

• Health– Health status– Desire to improve

health/appearance– Nutrition knowledge and attitudes

What is Nutrition? • Textbook

Terminology

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What is What is Nutrition?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

NutrientsNutrients

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

p. 96. i

NutrientsNutrients• 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

FoodsFoods

• Derived from plant or animal sources

• Provide energy and nutrients used by the body for growth, maintenance and repair

–2. p

DietDiet • The foods and beverages one

consumes affects• The quality of life now

• The risk of chronic diseases later

• 3. o

p. 10

Nutrient - Body Nutrient - Body CompositionComposition

60%

13-31%

Nutrients in the BodyNutrients in the Body• Example: 150# body

– Water = 90#– Fat = 20 -45#– Carbohydrate, Protein, Major Minerals

= 15 -40#– Vitamin, Minor Minerals = < 1#

EnergyEnergy• Energy defined:

– Capacity to do work– Fuel for the body– Calories– 13. e

• Basal Metabolism– 5. h

23

Carbohydrates 4 kcal/gram

Lipids 9 kcal/gram

Protein 4 kcal/gram

p. 12

17. a

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Functions of NutrientsFunctions of NutrientsNutrients Provide

EnergyPromote

GrowthMaintenance

Regulate Body

Processes

Carbohydrates X

Lipids X X X

Proteins X X X

Vitamins X X

Minerals X X

Water X X

More About NutrientsMore About Nutrients

Chemical composition of nutrientsOrganic- contains carbonInorganic- does not contain carbon

9. l10. m

The NutrientsThe Nutrients

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Essential NutrientsEssential 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.

11. f

NutrientsNutrients

• Macronutrients -12. g– Carbohydrates– Proteins– Fats

• Micronutrients– Vitamins– Minerals

Six Classes of Six Classes of Nutrients Nutrients

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Classes of Nutrients - OverviewClasses of Nutrients - Overview

• CarbohydratesCarbohydrates

• Lipids (fats)Lipids (fats)

• ProteinsProteins

• VitaminsVitamins

• MineralsMinerals

• WaterWater

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CarbohydratesCarbohydrates• A large class of

nutrients, including:– Sugars– Starch– Fibers

• Function:– Primary energy source

Lipids (Fats)Lipids (Fats)• A group of fatty

substances, triglycerides, that are not soluble in water– Fats, oils

• Provides energy and structure to cells

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ProteinProtein• Major structural parts

of the body’s cells made of nitrogen-containing amino acids assembled in chains.

• Rich in animal foods• Present in many plant

foods

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Vitamins and MineralsVitamins 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

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WaterWater• Inorganic nutrient that

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

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Food FactsFood Facts• Most foods provide a mix

of nutrients.

• Food contains more than just nutrients – food may contain colorings, flavorings, phytochemicals, caffeine, and other substances.

Nutrient Nutrient DensityDensity

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Nutrient DensityNutrient Density• Nutrient Density

– A measure of the nutrients provided in a food per kcalorie of the food.

• Empty-kcalorie foods– Foods that provide few/no nutrient for the number of

kcalories provided

8. k p. 13-14

Nutrient DensityNutrient Density• Which food item

has the greatest nutrient density?

• “NuVal”?

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Nutrient Density Comparison: % DRI intakes for selected nutrients.

p. 14

Energy DensityEnergy Density

• Energy Density–A measure of the energy a food

provides relative to the amount of food (kcal per gram)

• 14. d

Energy DensityEnergy Density

Nutritious DietNutritious Diet

ABCD Healthy Diet ABCD Healthy Diet Planning PrinciplesPlanning Principles

• AAdequate– Nutrient amounts sufficient to maintain health

• BBalance– Foods proportionate to each other and body’s

needs

• CCalorie control – Maintain healthy weight

–Moderation: Enough but not too much

Diet Planning PrinciplesDiet Planning Principles

• DDensity: – Caloric/Nutrient

• Empty-kilocalorie foods• Nutrient dense foods

• VARIETY!VARIETY!– Eating a wide selection– Whole foods

Fig. 2.15

Vegan Food Pyramid

ChooseMyPlate ExerciseAssignment for Next Week

• www.choosemyplate.gov• Super Tracker and Other Tools• Daily Food Plan

– Based on age, gender, activity level– View, Print and Learn

http://www.choosemyplate.gov/

50

Dietary Reference Intake (DRI)Dietary Reference Intake (DRI)

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

51

Dietary Reference Intakes (DRI)Dietary Reference Intakes (DRI)

• Recommended Dietary AllowanceRecommended Dietary Allowance (RDA)(RDA)Intake value sufficient to meet Intake value sufficient to meet nutrient requirements of 97-98% of nutrient requirements of 97-98% of all healthy individuals in a group, all healthy individuals in a group, based on age and gender.based on age and gender.

Iron- 19-50 y.o. men- 8 mg a dayIron- 19-50 y.o. men- 8 mg a day 19-50 y.o. women- 18 mg a day19-50 y.o. women- 18 mg a day

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Dietary Reference IntakesDietary Reference Intakes• Adequate Intake (AI)

Intake value used when a RDA cannot be based 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.

• 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

DRIDRI

How does the How does the body get its body get its nutrients?nutrients?

56

Digestion and AbsorptionDigestion and Absorption

• Digestion: Process by which food is broken down 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.

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““Digestibility”Digestibility”• 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

Unique GI Characteristics For Digestion and Absorption

• Anatomy- GI tract• Muscular Movement- Peristalsis• Secretions- enzymes/hormones• Physiology- structure of villi• Absorption- sites of nutrients• Elimination- stools and urine

Peristalsis

• Muscle movement • Effected by:

– Physical activity– Medications– Fiber Intake– Amount consumed– Diet composition– Stress– Illness

Secretions

• Saliva, mucous• Enzymes• Hormones• Acid, bicarbonate

Villi- Small Intestine

Provides for entry of nutrients into the blood

and lymph

Nutrient absorption area

introduction to nutrition chapter 1- week 1. objectives after reading chapter 1, class activities...

Documents

studies nutrients

human body

body water

science of foods

mthe nutrients

nutrient body composition60

particular foods

food choicesdefine