The Carbohydrates
Sugars
Starches
Fiber
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Carbohydrates
(CH2O)n
• Simple carbohydrates
–Monosaccharides
–Disaccharides
• Complex carbohydrates
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Simple
Carbohydrates
• Monosaccharides
–C6H12O6
•Glucose
•Fructose
•Galactose
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Glucose
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Fructose & Galactose
Condensation
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Hydrolysis
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Disaccharides
• Maltose
• Sucrose
• Lactose
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Complex
Carbohydrates
• Polysaccharides
–Glycogen
–Starches
–Fibers
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Glycogen & Starch Molecules
Compared (small Segments)
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Complex
Carbohydrates
• Fibers
–Cellulose
–Hemicelluloses
–Pectins
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Complex
Carbohydrates
• Fibers
–Gums and mucilages
–Lignin
–Resistant starches
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Complex
Carbohydrates
• Fibers
–Soluble fibers
•Viscous
•Fermentable
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Complex
Carbohydrates
• Fibers
–Insoluble fibers
•Nonviscous
• (Phytic acid)
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Digestion
• Mouth
–Salivary amylase
• Stomach
–Fibers and satiety
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Digestion
• Small intestine
–Maltase, sucrase, lactase
• Pancreas
–Pancreatic amylase
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Digestion
• Available carbohydrates vs.
unavailable carbohydrates
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Carbohydrate
Digestion in
the GI Tract
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Digestion
• Large intestine
–Fermentation of viscous fibers
•Water, gas, short-chain fatty
acid production
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Absorption
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Lactose Intolerance
• Symptoms
• Causes
–Lactase deficiency
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Lactose Intolerance
• Prevalence
• Dietary changes
–Does not require the elimination
of milk/milk products
–Acidophilus milk
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Glucose in the Body
• Energy
• Glycoproteins
• Glycolipids
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Carbohydrate
Metabolism
• Storing
glucose as
glycogen
• Using glucose
for energy
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Carbohydrate
Metabolism
• Making glucose from protein
–Gluconeogenesis
–Protein-sparing action of
carbohydrates
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Carbohydrate
Metabolism
• Making ketone bodies from fat
fragments
–Ketone bodies
•Ketosis
–Acid-base balance
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Carbohydrate
Metabolism
• Converting glucose to fat
–Energetically expensive
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Constancy of Blood
Glucose
• Regulating hormones
–Insulin
–Glucagon
–Epinephrine
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Maintaining Blood
Glucose
Homeostasis
Constancy of Blood
Glucose
• Diabetes
–Type 1 diabetes
•Failure of insulin production
–Type 2 diabetes
•Obesity
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Constancy of Blood
Glucose
• Hypoglycemia
–Rare in healthy people
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Constancy of
Blood Glucose
• Glycemic response
–Glycemic index
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Sugars
• Added sugars
–Sucrose, invert sugar, corn
syrups, etc.
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Sugars
• Health effects
of sugars
–Nutrient
deficiencies
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Sugars
• Health effects of
sugars
–Dental caries
•Dental plaque
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Accusations
Against Sugars
• Sugar causes
obesity
• Sugar causes
heart disease
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Accusations
Against Sugars
• Sugar causes misbehavior in
children and criminal behavior in
adults
• Sugar causes cravings and
addictions
–serotonin
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Recommended
Intakes of Sugars
• DRI
–No more than 25% of total daily
energy intake
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Starch and Fiber
• Health effects
–Heart
disease
–Diabetes
–GI health
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Starch and Fiber
• Health effects
–Cancer
–Weight management
–Harmful effects of excessive fiber
intake
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Viscous Fibers
• Soluble and more fermentable
• Gums and mucilages
• Pectins
• Psyllium
• Some hemicelluloses
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Viscous Fibers
• Sources
–Whole-grains, fruits, legumes,
seeds and husks, vegetables
–Extracted and used as food
additives
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Viscous Fibers
• Lower blood cholesterol
• Slow glucose absorption
• Slow transit of food through upper
GI tract
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Viscous Fibers
• Holds moisture in stools, softening
them
• Yield small fat molecules that the
colon can use for energy
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Viscous Fibers
• Lower risk of heart disease
• Lower risk of diabetes
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Viscous Fibers
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Nonviscous Fibers
• Insoluble and less fermentable
• Cellulose
• Lignins
• Psyllium
• Resistant starch
• Many hemicelluloses
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Nonviscous Fibers
• Sources
–Brown rice, fruits, legumes,
seeds, vegetables, wheat bran,
whole grains
–Extracted and used as food
additives
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Nonviscous Fibers
• Increase fecal weight
• Speed fecal passage through colon
• Provide bulk and feelings of
fullness
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Nonviscous Fibers
• Alleviate constipation
• Lower risks of diverticulosis,
hemorrhoids, appendicitis
• May help with weight management
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Nonviscous Fibers
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Starch and Fiber
• RDA for carbohydrate
–130 g/day
–45% - 65% total daily energy
intake
• Daily Value: 300 g/day
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Starch and Fiber
• Fiber
–Daily Value: 25 g/day
–AI: 14 g/1000 kcal/day
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Guidelines
to
Groceries
• Grains
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Guidelines
to Groceries
• Vegetables
• Fruits
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Guidelines
to Groceries
• Milk and milk products
• Meats and meat alternatives
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Alternatives to Sugar
• Artificial sweeteners vs. sugar
replacers (nutritive sweeteners)
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Alternatives to Sugar
• Saccharine and cancer
• Aspartame and PKU
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Metabolism
of Aspartame
Alternatives to Sugar
• Stevia
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Alternatives to Sugar
• Acceptable Daily Intake (ADI)
• Artificial sweeteners and weight
control
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Sugar Alternatives on Food Labels