1. Introduction to Nutrition

2. Learning Objectives:
 Consider factors that influence food
selection
 Define nutrition, calorie, nutrient, and
nutrient density
 Identify the classes of nutrients and their
characteristics
 Describe the 4 characteristics of a
nutritious diet

3. Learning Objectives
 Define Dietary Reference Intakes
 Compare and contrast the EAR, RDA, AI
and UL
 Explain the importance and function of the
Dietary Reference Intakes
 Describe the processes of digestion,
absorption and metabolism, and how the
digestive system works

4. Factors Influencing Food Selection
Values or
beliefs
Cultural
background
and religious
beliefs
Age,
gender,
occupation,
education
and income

5. Factors Influencing Food Selection
 Family influences
 Social influences
 Emotional influences

6. Factors Influencing Food Selection




Peer pressure
Familiarity with the
food
What you associate
the food with (ex.
Cakes for birthdays)
Nutritional value of
the food

7. Factors Influencing Food Selection



How the food smells,
looks and tastes
Cost, convenience
and availability of the
food
Your nutritional
knowledge and
concerns

8. Factors Influencing Food Selection



Desire to improve
your health
The media, including
advertising
Environmental
concerns

9. Nutrition

A science that studies
nutrients and other
substances in food and
how these nutrients
relate to health and
diseases

Explores why you
choose particular foods
and the type of diet you
eat

10. Nutrients
 The nourishing substances in food that
provide energy and promote the growth
and maintenance of your body
 Diet: the food and beverages that you
normally eat

11. Calories





A measure of the
energy in food,
specifically the
energy-yielding
nutrients
Based on 3 factors:
Basal metabolism
Physical activity
Thermic effect of food

12. Factors that Affect Basal
Metabolism

Gender: higher in
men

Age: declines 2-3%
per decade

Growth: higher in
children, pregnant
women and lactating
women

13. Factors that Affect Basal
Metabolism



Height: Tall thin
people have higher
BMR
Temperature:
increases in both hot
and cold
environments
Fever and stress:
increase BMR

14. Physiologic Fuel Value
 1 g carbohydrate = 4 kcal
 1 g fat = 9 kcal
 1 g protein = 4 kcal
 1 g alcohol = 7 kcal

15. Essential Nutrients for Human
Nutrient
Examples
Fat
Linoleic and Linolenic Acid
Carbohydrate
Glucose and Dietary Fiber
Protein
Vitamins
Minerals
Water
Amino Acids : Arginine, Histidine,
Isoleucine, Leucine, Lysine,
Methionine, Phenylalanine,
Threonine, Tryptophan, Valine
Fat-soluble : A, D, E and K
Water-soluble : Thiamin, Riboflavin,
Niacin, Folic Acid, Cobalamin,
Pyridoxine, Pantothenic Acid,
Biotin and Ascorbic Acid
Ca, P, Mg, S, Na, Cl, K, Fe, Cu, Mn,
Zn, Co, I, Mo, Se, Cr, Fl

16. Nutrient Density

A measure of the
nutrients provided in a
food per calorie of the
food

17. Characteristics of a Nutritious Food
 Adequate
 Balanced
 Moderate
 Varied

18. Dietary Reference Intakes
 Reference values that are quantitative
estimates of nutrient intakes to be used for
planning and assessing diets for
apparently healthy people

19. Estimated Average Requirement
(EAR)
 The daily dietary intake level that is
estimated to meet the nutrient requirement
of 50% of healthy individuals in a
particular life stage and gender group

20. Recommended Dietary Allowance

The standard deviation indicates the degree
of variation from the mean; in this case, it
indicates how different the nutrient
requirements of individual group members
are from the group mean

21. Adequate Intake (AI)
An observational standard that is used when
insufficient data is available to determine an
RDA from an existing EAR
 Because it is set using presumable healthy
groups of individuals, the AI is expected to
meet or exceed the actual nutrient
requirement in all healthy members of a
specific life stage and gender group


22. Tolerable Upper Level
 The highest level of daily nutrient intake
that is likely to pose no risk of adverse
health effects to almost all apparently
healthy individuals in the general
population
 As intake increases above the UL, the
risk of adverse (toxic) effects increases

24. 
Digestion : the process by which food is
broken down to absorbable units.

Gastrointestinal tract : flexible muscular tube
from the mouth through the esophagus,
stomach, small intestine, large intestine, and
the rectum to the anus.

Absorption : the passage of nutrients from the
GI tract into either the blood or the lymph.

26. 


Mouth : the oral cavity containing the
tongue and teeth.
Pharynx : the passageway leading from the
nose and mouth to the larynx and
esophagus, respectively.
Epiglottis : cartilage in the throat that
guards the entrance to the trachea and
prevents fluid or food from entering it when
the person swallows.

28. 


Esophagus : the food pipe; the conduit from
the mouth to the stomach.
Sphincter : a circular muscle surrounding,
and able to close a body opening. Sphincters
are found at specific points along the GI tract
and regulate the flow of food particles.
Stomach : a muscular, elastic, saclike
portion of the digestive tract that grinds and
churns swallowing good, mixing it with acid
and enzymes to form chime.

30. 


Pyloric sphincter : the circular muscle that
separates the stomach from the small intestine
and regulates the flow of partially digested food
into the small intestine.
Gallbladder : the organ that stores and
concentrates bile. When it receives the signal that
fat is present in the duodenum, the gallbladder
contracts and squirts bile through the bile duct
into the duodenum.
Pancreas : a gland that secretes digestive
enzymes and juices into the duodenum.

32. 
Small intestine : a 10-ft length of smalldiameter intestine that is the major site of
digestion of food and absorption of
nutrients. Its segments are the
duodenum, jejunum and ileum.

Lumen : the space within a vessel, such
as the intestine.

33. 
Duodenum : the top portion of the small
intestine

Jejunum : the first two-fifths of the small
intestine beyond the duodenum.

Ileum : the last segment of the small
intestine.

Ileocecal valve : the sphincter separating
the small and large intestines.

35. 


Large intestine (colon): the lower portion
of the small intestine that completes the
digestion process. Its segments are the
ascending colon, the transverse colon, the
descending colon and the sigmoid colon.
Rectum : the muscular terminal part of the
intestine, extending from the sigmoid colon
to the anus.
Anus : the terminal outlet of the GI tract.