Carbohydrates

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Carbohydrates
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What are Carbohydrates?

• CHO make up 3 of the bodys organic matter
• CHO are compounds constructed in a ratio of one
  atom of carbon and two atoms of hydrogen for each
  oxygen atom
• Chemical Formula (CH2O)n
• Where n is from 3 to 7 carbon atoms
• 5 carbon sugars are called pentoses
• 6 carbon sugars are called hexoses (most common)

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Carbohydrate2 Hydrogen for each Oxygen
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Glucose - C6H12O6
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Categories of Carbohydrates

• Monosaccharides (glucose, fructose, galactose
• Disaccharides (sucrose, maltose, lactose)
• Polysaccharides (starch, fiber, glycogen)

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Monosaccharides

• Glucose
• Fructose
• Galactose

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Dissaccarides

• Combination of 2 or more monosaccharides
• Mono Disaccharides SIMPLE SUGARS
• Sucrose glucose fructose (brown sugar
• 25 of sugar intake)
• Lactose glucose galactose (milk
• sugar least sweet)
• Maltose glucose glucose (honey)
• Natural Sweetness

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Is Refined Sugar a Villain?

• To much sugar results in eating less of something
  else - Sugar Causes Malnutrition
• Eating sugar without eating less of something
  else, results in enough nutrients but too many
  kCal - Sugar Causes Obesity
• Excess sugar converts to fat and so causes
  hyperlipidemia - Sugar Causes High Levels of
  Blood fat and Atherosclerosis
• Concentrated sugar is not natural and dangerous
• Sugar causes diabetes
• Sugar causes tooth decay

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Polysaccharides3 or more simple sugars combined
Plant Polysaccharides Starch peas, seeds, corn,
gains, cereals, potatoes, roots Cellulose fibe
r (technically not a nutrient)
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Polysaccharides

• Animal Polysaccharides - GLYCOGEN
• Ranges in size from a few hundred to thousands of
  glucose molecules linked together like sausage
  links
• 375-475 g stored in body (liver, muscle, kidney)
• Can be modified by diet and exercise

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Animal Polysaccharides

• Glycogen
• Large molecules
• Stored in liver (100 g) and muscle (325 g)
• Because little glycogen is stored - it can be
  modified by diet and exercise
• Why do we want to conserve muscle glycogen?
• Glucose intake during exercise 70g/140 H2O, 20-30
  min prior to exercise

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CHO Conversions

• GLYCOGENESIS Glycogen derived from glucose
• Glycogenolysis In liver, glucose derived from
  glycogen
• Gluconeogenesis In liver, glucose derived from
  protein (non CHO products)

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Dietary Fiber

• Water insoluble fibers cellulose, hemicellulose,
  lignins, pectins, gums, wheat bran
• Water soluble fiber oats, beans, rice, peas,
  carrots, fruits
• Health Implications of Fiber obesity, diabetes,
  intestinal disorders, cancer, cholesterol
  effects
• Recommended intake of fiber 20-30 g/d
• Americans eat about 12 g/d
• Africans eat about 40-150 g/d
• Guess who has the highest incidence of colorectal
  cancer?

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Not All CHO The SameThe Glycemic Index
GI a relative measure of the extent to which
blood glucose increases after ingesting 50 g of
CHO.
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Functions of CHO

• Energy Source
• Protein Sparing
• Metabolic Primer
• CNS Fuel

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Sources of CHO
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What Happens when you Consume CHO?
Blood Glucose
Liver Glycogen
Muscle Glycogen
Adipose Tissue
Kidney Excretion
Used for Energy
Type, duration, intensity
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Hypoglycemia v Hyperglycemia

• Hypoglycemia - low blood sugar hormones
  (glucagon) stimulate liver to release sugar into
  blood
• Hyperglycemia - high blood sugar insulin aids
  sugar uptake from blood to cells with excess
  blood sugar, spills out to kidneys and is
  urinated out (sweet urine).

Sensitivity v underproduction
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CHO and Endurance Exercise