Carbohydrates:
The Energy Nutrient
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.
Dr. Latifah Al-Oboudi 2012
CARBOHYDRATES
1.
Functions of Carbohydrates
Energy
2.
Regulation
3.
Structure

Dr. Latifah Al-Oboudi 2012
Carbohydrates
Two kinds:
1.
Simple
2.
Complex
Dr. Latifah Al-Oboudi 2012
Simple Sugars
Monosaccharides
What are they?

A 6 Carbon ring with a water attached

Monosaccharides = One Sugar

3 Types : glucose, fructose and galactose
Which is sweetest?
Dr. Latifah Al-Oboudi 2012
Monosaccharides
Figure 4.2
Dr. Latifah Al-Oboudi 2012
Simple Sugars
1. Glucose
 Blood sugar

Basic “currency” of
energy in the body

Storage = glycogen
Dr. Latifah Al-Oboudi 2012
Simple Sugars)
2. Fructose
 Major sugar found in fruit and honey
 Sweetest monosaccharide
Where else is Fructose found in your food?
 Sunny Delight
 Cereals
 Cookies
Dr. Latifah Al-Oboudi 2012
Simple Sugars
3. Galactose
 Rarely found by itself in food…complex with
glucose
 Its ½ of the milk sugar “Lactose”
Lactose = galactose + glucose

What does it Mean if you are “Lactose Intolerant”?
Dr. Latifah Al-Oboudi 2012
Simple Sugars: Disaccharides
 Maltose
 Sucrose
 Lactose
Dr. Latifah Al-Oboudi 2012
Disaccharides
Figure 4.3
Dr. Latifah Al-Oboudi 2012
Disaccharides
1. Sucrose
Glucose + Fructose
Each contain a 6-Carbon ring and water
Food Sources: Candies, cake, cookies, table sugar
Dr. Latifah Al-Oboudi 2012
Disaccharides
2. Maltose
 Glucose + Glucose
 Uncommon in food sources, except barley
 Breakdown product of Starch
 Product of fermentation  Alcohol
Dr. Latifah Al-Oboudi 2012
Disaccharides
3. Lactose
 Glucose + Galactose
 Milk Sugar
Food Sources:
 Milk, Yogurt, Cheese, Ice Cream
 One of a very few sugars found in animal products
Dr. Latifah Al-Oboudi 2012
Oligosaccharides

Sources: dried beans,
soybeans, peas,
lentils

Components of cell
membranes
 Humans lack
enzymes to digest
oligosaccharides
causing bloating,
cramps, & gas
Dr. Latifah Al-Oboudi 2012
Complex Carbohydrates

Polysaccharides
Dr. Latifah Al-Oboudi 2012
Complex Carbohydrates
Figure 4.4
Dr. Latifah Al-Oboudi 2012
Complex Carbohydrates
Polysaccharides
1- Glycogen
• Made and found in our bodies
• Not found in plants
• Storage form of Carbohydrate in the body
• Saved for later use
• Stored in liver and muscle
Dr. Latifah Al-Oboudi 2012
Complex Carbohydrates
Polysaccharides
2- Starches


Most common food polysaccharide
Long branched or unbranched chain of glucose molecules
Food sources of starch:
Vegetables: yams, corn, potatoes
Legumes: peas, beans
Grains: wheat, rice, oats, breads, pasta, barley, rye
 Unripe Fruit
Dr. Latifah Al-Oboudi 2012
Complex Carbohydrates
Polysaccharides
3- Fiber


Only found in plants
We don’t have fiber
digesting enzymes
Dr. Latifah Al-Oboudi 2012
FIBER
What exactly is fiber?
Dr. Latifah Al-Oboudi 2012
Pick “Whole Grains” & “Whole
Wheat”!
2 main categories of fiber
1. Insoluble fiber (does not dissolve in water)
2. Soluble fiber
Dr. Latifah Al-Oboudi 2012
FIBER
Water Soluble (Dissolves in water)- form gels
 What
does it do in your body?
Dr. Latifah Al-Oboudi 2012
Fiber
Why can Cows eat grass and digest it for
energy but humans can not?
Cows have bacteria to break down fiber
to glucose  energy
Dr. Latifah Al-Oboudi 2012
Increasing Dietary Fiber Intake
Dr. Latifah Al-Oboudi 2012
FIBER
Poor Fiber Intake Results in:



Small waste = moves slow in GI tract
Body takes water out of waste => dry and hard stool
Must strain to expel this dry, hard waste =
• Constipation
• Diverticula
• Hemorrhoids
Dr. Latifah Al-Oboudi 2012
Dr. Latifah Al-Oboudi 2012
Dr. Latifah Al-Oboudi 2012
 Diverticular

Disease
Caused from: hard, dry feces, characteristic
of a low-fiber diet
 Prevention

Diet high in fiber
Plenty of fluids

Diverticulosis and Fiber

Dr. Latifah Al-Oboudi 2011
FIBER
Health Benefits:
Decreased Risk for:
Dr. Latifah Al-Oboudi 2012
Dietary Fiber Benefits

High water-holding capacities

Fermentable fibers
Dr. Latifah Al-Oboudi 2012
FIBER
Review:
How can you tell if a food contains any fiber?
*Remember…
NO food from animal sources have fiber


Chicken, Eggs, Tuna?
Potatoes, whole wheat bread, whole grain
cereal, pinto beans, zucchini, apples?
*Best Sources:
Dr. Latifah Al-Oboudi 2012
Carbohydrates: Digestion
What happens when you eat a carbohydrate
meal: milk, bagel with jam
MILK: Lactose (disaccharide)
Bagel: Starch (polysaccharide)
Jam: Sucrose (disaccharide)
Doesn’t take much to break down a
disaccharide….but what about the starch?
Dr. Latifah Al-Oboudi 2012
Carbohydrates: Digestion
Eat milk, bagel and jam
Mouth:
Small Intestine:
* Now…bagel starch = maltose
jam = sucrose
milk = lactose
Dr. Latifah Al-Oboudi 2012
Carbohydrates: Digestion

Eat milk, bagel and jam

Each Disaccharide has its own enzyme that
breaks it down to a Monosaccharide
Disaccharide
Maltose
Sucrose
Lactose
Enzyme
Maltase
Sucrase
Lactase
End Product
glucose & glucose
glucose & fructose
glucose & galactose
Dr. Latifah Al-Oboudi 2012
Dr. Latifah Al-Oboudi 2012
Carbohydrates
How Does Glucose get into our cells?
Glucose + Insulin  Inside Cells
Then, what do we do with it?
Dr. Latifah Al-Oboudi 2012
Dr. Latifah Al-Oboudi 2012
Dr. Latifah Al-Oboudi 2012
Carbohydrates
What if cells don’t get glucose?
No Insulin  No glucose in Cells  Starved Cells
No Insulin  Type I Diabetes  Require Insulin
Not responsive to insulin  Type II Diabetes
Dr. Latifah Al-Oboudi 2012
Metabolism
Process by which nutrients are
broken down to yield energy or
rearranged into body structures
Dr. Latifah Al-Oboudi 2012
Carbohydrate Energy
 How

does glucose become energy?
Each of the 6 Carbon bonds of glucose can be
broken for energy
 End
products of carbohydrate energy
metabolism:
CO2, Water, Energy (4 kcal/g carbohydrate)
Dr. Latifah Al-Oboudi 2012
Carbohydrates

Excess glucose stored as glycogen
How much can we store?
 What
foods contain glycogen?
Dr. Latifah Al-Oboudi 2012
Carbohydrates
What if we run out of glycogen stores?
Dr. Latifah Al-Oboudi 2012
Carbohydrate Energy Use
What if I eat 10 bagels, a jar of jam and a carton of
milk for breakfast?
Eat too much carbohydrate  Stored as fat
Dr. Latifah Al-Oboudi 2012
Carbohydrate Energy
What if I didn’t eat anything for days or a very low CHO
diet?
 Use up my glycogen stores for energy
-Depleted in 24-36 hrs
 Protein broken into amino acids  blood
-Form glucose from amino acid
-Nitrogen goes to the kidney as waste
-Helps provide fuel for brain

Fats are not a significant source of glucose
Dr. Latifah Al-Oboudi 2012
Carbohydrate Energy
Consequences of breaking down Protein for
Fuel?
 No storage form of proteins
 So this takes functional-needed protein from
the body
How can this be prevented?
Dr. Latifah Al-Oboudi 2012
The Need for Carbohydrates
 The
DRI committee recommends:
Dr. Latifah Al-Oboudi 2012
Sugars

Health effects of
excess sugars

Cavities
Dr. Latifah Al-Oboudi 2012
Carbohydrates
TOO MUCH of a GOOD THING?

Think in terms of caloric intake
 Empty

Calories
Don’t over indulge…limit sugar intake to 10% of
calories (200 g for 2,000 kcal diet)
Dr. Latifah Al-Oboudi 2012
Carbohydrates
TOO MUCH of a GOOD THING?

UNPROVEN Health Effects of Excess CHO intake
1.
2.
3.
4.
5.
Causes Obesity?
Causes Diabetes?
Causes Heart Disease?
Causes Kids to Misbehave?
Causes Criminal Behavior?
Dr. Latifah Al-Oboudi 2012
Diabetes
 Do
carbohydrates cause diabetes?
NO!
 Type I


Less common
Pancreas does not make insulin
 Type



2
Most common and on the rise
Linked to being overweight
Fat cells are resistant to insulin
Dr. Latifah Al-Oboudi 2012
Alternatives to Sugar
 Artificial
sweeteners (nonnutritive) vs. sugar
alcohols (nutritive sweeteners)
Dr. Latifah Al-Oboudi 2012
Artificial Sweetners

Aspartame
Saccharin

Sucralose

Stevia- Herbal alternative, not approved
by the FDA for widespread use

Dr. Latifah Al-Oboudi 2012
Alternative Sweeteners
Figure 4.17
Dr. Latifah Al-Oboudi 2012
Dr. Latifah Al-Oboudi 2012
Alcohol
 Contributes
7 calories/g
 2-carbon molecule made from fermented
carbohydrates
 IT IS NOT A NUTRIENT
 Can adversely affect liver function, caloric
intake, absorption, metabolism and
excretion.
Dr. Latifah Al-Oboudi 2012
Alcohol
Fermentation
Carbohydrate
Ethanol
Dr. Latifah Al-Oboudi 2012