Transcript Dietary Fiber

Chapter 2
Carbohydrates
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Slide 1
Chapter 2
Lesson 2.1
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Slide 2
Key Concepts
• Carbohydrate foods provide practical energy
(calorie) sources because of their availability,
relatively low cost, and storage capacity.
• Carbohydrate structures vary from simple to
complex, so they can provide both quick and
extended energy for the body.
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Slide 3
Importance of Carbohydrates
•
•
•
•
Basic fuel source
Widely available and easily grown
Relatively low in cost
Easily stored
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Slide 4
Classes of Carbohydrates
• Monosaccharides
 Glucose
 Fructose
 Galactose
(Cont'd…)
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Slide 5
Classes of Carbohydrates
(…Cont’d)
• Disaccharides
 Sucrose
 Lactose
 Maltose
(Cont'd…)
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Slide 6
Classes of Carbohydrates
(…Cont’d)
• Polysaccharides
 Starch
 Glycogen
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Slide 7
Summary of Carbohydrate
Classes
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Slide 8
Chapter 2
Lesson 2.2
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Slide 9
Key Concepts
• Dietary fiber, an indigestible carbohydrate,
serves separately as a body regulatory agent.
• Carbohydrate foods provide practical energy
(calorie) sources because of their availability,
relatively low cost, and storage capacity.
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Slide 10
Dietary Fiber
• Not digestible
• Important in health promotion and disease
prevention
• Cellulose
 Remains undigested in the GI tract and
provides bulk to a diet
 Bulk helps move the food mass through the
intestine
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Slide 11
Dietary Fiber
(…Cont’d)
• Noncellulose polysaccharides
 Absorb water and swell to a larger bulk
• Lignin
 Only noncarbohydrate type of dietary fiber
(Cont'd…)
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Slide 12
Dietary Fiber
(…Cont’d)
• Divided into two groups based on solubility
• Dietary fiber provided in whole grains,
legumes, vegetables, fruits
• Many health organizations recommend
increasing intake of dietary fibers
(Cont'd…)
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Slide 13
Dietary Fiber
(…Cont’d)
• Sudden increases can result in gas, bloating,
constipation
• Excessive amounts of dietary fiber can trap
small amounts of minerals and prevent
absorption into GI tract
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Slide 14
Summary of Dietary Fiber
Classes
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Slide 15
Other Sweeteners
• Nutritive sweeteners
 Sugar alcohols (sorbitol, mannitol, xylitol)
• Nonnutritive sweeteners
 Artificial sweeteners in food
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Slide 16
Sweetness of Sugars and
Artificial Sweeteners
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Slide 17
Energy Function of
Carbohydrates
• Basic fuel supply
 Energy for physical activities and all work of
body cells
• Reserve fuel supply
 Provided by glycogen
 Maintains normal blood glucose level
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Slide 18
Special Tissue Functions of
Carbohydrates
• Liver
 Glycogen reserves protect cells from
depressed metabolic function
• Protein and fat
 Carbohydrates regulate proteins and fat
(Cont'd…)
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Slide 19
Special Tissue Functions of
Carbohydrates
(…Cont’d)
• Heart
 Glycogen is vital emergency fuel for heart
muscle
• Central nervous system
 Brain dependent on minute-to-minute supply
of glucose
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Slide 20
Food Sources of
Carbohydrates
• Starches
 Provide fundamental complex carbohydrates
• Sugars
 High-sugar diets carry health risks
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Slide 21
Carbohydrate Content of
Foods
(Cont'd…)
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Slide 22
Carbohydrate Content of
Foods
(…Cont’d)
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Slide 23
Digestion of Carbohydrates
• Mouth
 Mechanical or muscle functions break food
mass into smaller particles
• Stomach
 Peristalsis continues mechanical digestive
process
(Cont'd…)
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Slide 24
Digestion of Carbohydrates
(…Cont’d)
• Small intestine
 Peristalsis continues mechanical digestions
 Pancreatic secretions
 Intestinal secretions
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Slide 25
Summary of Carbohydrate
Digestion
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Slide 26
Body Needs for
Carbohydrates
• Dietary Reference Intakes
 45%-65% of adult’s total caloric intake should
come from carbohydrate foods
 Limit sugar to no more than 25% of calories
consumed
• Dietary Guidelines for Americans
 Does not outline specifics for caloric
consumption or where kilocalories should
come from
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Slide 27