Carbohydrates: The
Preferred Body Fuel
Chapter 5
Types of Carbohydrates
Carbohydrates
Made of 3 common chemical elements:
carbon
hydrogen
oxygen
Elements bond together to form
saccharides or sugar units.
Arrangement of sugar units determines
the type of saccharide.
Monosaccharides
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Composed of single sugar units
Glucose
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Fructose
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Sometimes called blood sugar
Body’s source of energy.
Sweetest taste of all sugars.
Found naturally in fruits and honey.
Galactose
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Bonded together with glucose.
Is the sugar found naturally in milk.
Disaccharides
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Made up of two sugar units. (di)
Body splits into monosaccharides during digestion.
Mono and Disaccharides are collectively referred to as sugars.
Sucrose
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Lactose
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Sugar you use at the table or in recipes.
One molecule glucose and one molecule fructose
Examples: beet sugar, cane sugar, molasses, maple syrup.
Found in milk.
One molecule glucose and one molecule galactose.
Serves as source of energy for breast-fed infants.
Maltose
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Found in certain grains such as malt
Two glucose molecules bonded together.
Formed during the digestion of starch.
Polysaccharides
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Carbohydrates that are made up of many sugar units.
Long straight chains or branched chains.
Must be broken down during digestion.
Starch
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Storage form of energy in plants.
Many glucose molecules bonded together.
Examples: breads and cereals, starchy vegetables such as corn,
potatoes, and legumes.
Fibers
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Make up the tough, fibrous cell walls of plants.
Found only in plants.
Human digestive enzymes cannot digest fiber.
Pass through digestive tract unchanged thus provide almost no
energy (calories)
Cellulose, gums and pectin are some types.
Simple and Complex
Carbohydrates
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Simple carbohydrates
Monosaccharides & Disaccharides
 Foods include sugar, candy, syrups and
soft drinks.
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Complex Carbohydrates
Polysaccharides
 Foods high in starch and fiber; breads,
cereals, rice, pasta and vegetables.
 Health benefits in choosing complex
carbohydrates over simple carbohydrates.
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Alcohol
Not a type of carbohydrate.
 Made by the fermentation of
carbohydrates from plant products.
 An energy yielding drug, 7 calories per
gram.
 Ethanol is the type consumed in diet.
 No health benefits to young peopleinstead risk of alcohol abuse increases
if drinking starts at early age.
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Functions of Carbohydrates
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Serve four key functions.
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Provide energy
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Spare proteins
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Provide 4 calories of energy per gram.
Preferred source of energy because body can use so efficiently.
By eating sufficient carbohydrates you spare the proteins from being
used for energy and can instead be used to build and maintain cell
structures.
Assist in the breakdown of fats
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If diet is too low in carbohydrates body cannot completely break down
fats.
Ketone bodies – ketosis: blood becomes more acidic than normal. Can
damage cells and organs.
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Nail polish smelling breath, nauseous and weak.
Provide bulk in the diet.
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Fiber is responsible for this.
Helps the intestinal muscles retain their tone.
Prevents constipation, reduces likelihood of hemorrhoids.
Benefits and Effects of Fiber
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Plenty of fiber in a low-fat diet can prevent:
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Soluble fibers
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Appendicitis
Lower risk of heart and artery disease.
Reduce risk of colon cancer.
Controls diabetes mellitus.
Dissolve in water and develop a gel-like consistency.
Help lower blood cholesterol levels
Examples: oat bran, legumes and apple and citrus pectins.
Insoluble fibers
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Do not dissolve in water.
Reducing of cancer risks.
Examples: Wheat bran, and whole grains.
How Your Body Uses
Carbohydrates
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All carbs must be in the form of glucose for your cells to use them as
energy.
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Hormone called insulin released from pancreas.
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Convert glucose to glycogen (body’s storage form of glucose)
Stored in muscles and liver
Liver can only store a limited amount of glycogen
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Release caused by rise of glucose in the blood after eating.
Hormones- chemicals produced by body to regulate body processes.
Insulin – helps the body lower blood glucose back to normal levels.
If no immediate energy need cells will store glucose.
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Broken down by digestion, glucose moves across the intestinal wall into
blood stream.
Travel to the liver.
Need to eat carbs throughout day to replenish glycogen.
Simple carbs vs. complex carbs
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Simple give quick digestion and short spurt of energy.
Complex gives satiety-feeling of fullness longer.
Meeting Your Carbohydrate
Needs
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Sugars
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Naturally Occurring
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Found naturally in foods such as lactose or fructose.
Not of great concern since these foods also contain other
nutrients needed by the body.
Refined
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Sugars added to food at the table or during processing.
Come from sugar cane, sugar beets and corn.
Main source for teens are soft drinks.
Many hidden sugars in cereals and ketchup.
Increase the calories without increasing the nutrients.
Fat free and reduced fat foods contain high amounts of sugar.
If on a 2000 calorie diet only 500 calories should come from
refined sugar: 31 teaspoons or no more than 40 oz. of soft
drinks.
Meeting Your Carbohydrate
Needs
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Starches
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Preferred source of energy for diet.
Starchy foods also excellent source of vitamins, minerals, and
fiber.
Recommendation that 20% of your calories come from complex
carbohydrates.
Starchy foods include breads, cereals, rice, pasta, vegetables and
legumes.
Fiber
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DRI 38 grams for males. DRI 36 grams for females.
Increase fiber by choosing whole grain products – these contain all
3 edible parts of the grain kernel; the bran, the germ, and the
endosperm.
Refined grain products have had the bran and germ and most of
the fiber removed during processing.
Fiber Supplements- not as good as natural sources, usually found
in pill, liquid or powder form.
When adding fiber do so gradually and drink plenty of water.
Meeting Your Carbohydrate
Needs
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Using Food Labels to Meet Your
Carbohydrate Needs
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Total carbs are listed in grams.
Also lists number of grams of dietary fiber and of
sugar.
Labels can help you find foods that contain added
carbohydrates.
Ingredients on label are listed in the order of
weight, with the heaviest listed first.
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If sugar is near the top of the list the product is mainly
sugar.
Also check for different types of sugars.
Health Questions Related to
Carbohydrates
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Are Starchy Foods Fattening?
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They contain less than ½ the calories of fat. Only 4 calories per
gram.
May be thought to be fattening because of how they are served:
sauces on pasta, sour cream and butter on potatoes.
Is Sugar a Hazard to Your Teeth?
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A clear connection between sweets and dental caries.
Sugars and starches can promote tooth decay.
Plaque comes from a sticky substance made by bacteria that live
in your mouth and feed on carbs.
Risk of dental caries depends on 2 main factors:
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Type of food you eat
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Sticky foods that tend to cling to teeth can be more harmful.
Sugars in baby formula sitting on the teeth as the child sleeps.
When you eat
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In between meal snacks- sugar stays in mouth longer.
Drink plenty of water to wash the teeth.
Clean babies teeth and gums after feeding them.
Health Questions Related to
Carbohydrates
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Does Sugar Cause Hyperactivity?
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Is Sugar Addictive?
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Hyperactivity is a condition in which a person seems to be in constant motion and is
easily distracted.
No scientific proof this is true.
A diet high in sugar can mean the child is missing some important nutrients that may
be tied to the lack of concentration.
Not proven scientifically.
We are born with a preference for sweet tasting foods.
Need for sugar is more psychological than physiological.
Will Too Much Sugar Cause Diabetes?
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Diabetes mellitus – the lack of or an inability to use the hormone insulin.
Type I – insulin dependent
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Pancreas not able to produce insulin.
Must take daily injections of insulin.
Type II – noninsulin-dependent diabetes
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Body cells do not respond well to the insulin the pancreas makes.
Can be controlled by diet and exercise.
Symptoms:
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Excessive thirst and hunger, weakness, irritability, and nausea. Changes in eyesight, slow healing of
cuts, drowsiness, and numbness in legs, feet or fingers too.
Heredity more than eating sugar is the cause.
Health Questions Related to
Carbohydrates
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What is Hypoglycemia?
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Refers to a low blood glucose level.
Overproduction of insulin cause the sharp drop in blood
sugar.
Symptoms: sweating, shaking, headaches, hunger, and
anxiety.
Dietary advice: avoid eating large amounts of sugar all at
once.
What is Lactose intolerance?
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Inability to digest lactose, the main carb in milk.
Symptoms: gas, cramping, nausea, and diarrhea after
consuming milk products.
Found in non-white people more often and as people age.
If intolerant of lactose must work hard to be sure to get
your needed requirements of calcium and Vit.D
May need medication to help in breaking down the lactose.