2. April 19, 2012
Digestion Basics
1. Mouth: Saliva has an enzyme that
begins to break down starch (bolus)
2. Esophagus: Muscular tube
3. Stomach: Acids and enzymes digest
food further (chyme)
4. Small intestine: Enzymes produced here
and by the pancreas break down food
further and nutrient molecules are
absorbed into the blood across the walls
of the small intestine.
20' in length: duodenum, jejunum, ileum
3. April 19, 2012
5. Large Intestine: Unabsorbed food
moves into here and water is removed
and some vitamins from undigested food.
6. Rectum: Waste is expelled from the
body.
5. April 19, 2012
* Nutrition is the study of...
- Food and how the body uses food
- How and why we make food choices
- Nutrients foods contain
* What are benefits of good nutrition?
6. April 19, 2012
* 6 Classes of Nutrients
- Carbohydrates
- Fat
- Protein
- Vitamins
- Minerals
- Water
7. April 19, 2012
Carbohydrates
* Provide 4 cal/g (with 1 exception)
* Include:
- sugars = "simple"
- starches = "complex"
- fiber (The weird carb, has 0 calories)
8. April 19, 2012
*What happens when you consume
carbohydrates?
1. Breaks down into glucose
2. If blood glucose too high, pancreas
reacts and excess is stored in liver and
muscles as glycogen
3. When glycogen stores are full, it
converts to fat
9. April 19, 2012
Two Types of Fiber (the weird carb)
1. Soluble
- Dissolves in water
- Cholesterol
2. Insoluble
- Does not dissolve in water
- Solid waste
10. April 19, 2012
Fat
* Provide 9 cal/g
* When too much in blood, it's stored as
triglycerides (3 fatty acids + 1 glycerol) in
the fat cells
* 2 Types of fat
- Saturated:
* Usually solid at room temperature
* Derived from animal foods
- Unsaturated:
* Usually liquid at room temperature
* Derived from plants
11. April 19, 2012
Cholesterol
(assoc. with saturated fat)
* Made by the body and obtained through
animal foods
* 2 Types:
- LDL (bad): Can cause plaque
formation in blood vessels
- HDL (healthy): Carries cholesterol to
liver to be removed from blood
12. April 19, 2012
Protein
* Provides 4 cal/g
* Protein builds, repairs, and maintains
body tissues
* Protein is found in:
- Muscles
- Bones
- Blood
- Hormones
* Amino acids = the building blocks that
make up protein
- Nonessential amino acids:
produced by body (11)
- Essential amino acids:
must obtain through diet (9)
13. April 19, 2012
2 Types of Protein
Complete Protein Incomplete Protein
From animal sources From plant sources
Contain all essential Do not contain all
amino acids essential amino
acids
Ex: Meat, fish, Ex: Nuts, seeds,
chicken, turkey, milk, beans
yogurt, eggs
14. April 19, 2012
The Vegan Diet
* Vegan = Person whose diet does not
include foods derived from animals.
* How do they get complete protein?
* Protein Loading = Eating strategy in
which extra protein is eaten to increase
muscle size.
* Extra protein does not increase muscle
size. Resistance exercise increases
muscle size. If eat more protein than
body needs, it's stored as fat.
15. April 19, 2012
U.S. RDA for protein =
.36 g x body weight
weight (lbs) protein RDA (g)
100 36
120 43
140 50
160 58
(Milk carton = 8 g)
16. April 19, 2012
Vitamins
* Provide 0 cal/g
* Fat soluble vitamins (A, D, E, & K) can be
stored in the body
- Toxic if overdose on dietary supplements
containing FSV (Hypervitaminosis)
* Water soluble vitamins (B & C) cannot be
store in the body in significant amounts
- Not toxic because can excrete excess
WSV
17. April 19, 2012
Minerals
* Provide 0 cal/g
* Make up 5% body weight
* Macrominerals: Found in body in amounts
>5g
- Electrolytes: Sodium, Potassium, Chlorine
* Trace Minerals: Found in body in amounts
<5g
18. April 19, 2012
Water
* Provide 0 cal/g
* Consume 8+ glasses/day
(and 2 glasses/lb lost after exercise)
* Makes up ~60% of our bodies
* Lost through:
- Urine and solid waste
- Breathing
- Skin
* Dehydration = Water consumed is less
than body uses
