introduction to nutrition chapter 1- week 1. objectives after reading chapter 1, class activities...
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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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Factors Influencing What You EatFactors Influencing What You Eat
• 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
Factors Influencing What You EatFactors Influencing What You Eat
• Cost• Convenience• Availability• Income
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Factors Influencing What You EatFactors Influencing What You Eat
• Social and Emotional Influences– Social status– Peer pressure– Emotional status– Food associations
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Factors Influencing What You EatFactors Influencing What You Eat
• Food Industry and the Media– Food industry
– Food advertising– Food portrayal in
media– Reporting of
nutrition/health studies
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Factors Influencing What You EatFactors Influencing What You Eat
• Environmental Concerns– Use of synthetic fertilizers
and pesticides– Production techniques
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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
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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.
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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
DRIDRI
How does the How does the body get its body get its nutrients?nutrients?
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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
More on FoodMore on Food
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Types of FoodTypes of Food1. Whole foods – fresh, unprocessed2. Fresh foods – raw, no preservatives3. Processed foods – procedure applied
• Canning, freezing, dehydrating, milling4. Enriched foods – nutrients replaced5. Fortified foods – nutrients added
p. 26-29
Types of FoodTypes of Food
• Imitation foods (cheese, milk) • Food substitutes (egg)
Functional FoodsFunctional Foods• Provide health benefits beyond nutrient
contributions
– Whole foods• Provide phytonutrients- blueberries, garlic
– Fortified foods• Calcium and vitamin D fortified orange juice
– Modified foods • “Engineered” or “designer”• Margarine containing plant sterols
– 4. n