Download CHO`s

We already know…
Carbohydrates
• CHO
• Energy yielding: 4 kcal/g
• Macronutrient
Chapter 4
What foods is it in?
• Grains
• Vegetables
• Especially starchy ones!
•
•
•
•
Fruit
Milk
Legumes
Sugary foods
CHO Classifications
• Complex carbohydrates aka
Polysaccharides: large chains of
monosaccharides
• Starch
• Glycogen
• Some fibers
CHO Classifications
• Simple carbohydrates: sugars
• Monosaccharides: single sugars
• Disaccharides: pairs of monosaccharides
Sugars: Monosaccharides
• Glucose: (aka dextrose) the principle
building block of CHO
• Component of di- and poly• aka blood sugar--the chief energy
source for the body's cells
1
Sugars: Monosaccharides
• Fructose: the sweetest of the sugars
• aka fruit sugar
• in fruits, honey, also made in highfructose corn syrup
CHO: Building and Breaking
• CHO are linked together through
condensation (water is removed)
• Hydrolysis (water is added) reactions
break down CHO
Sugars: Disaccharides
• Maltose: not in many foods
• a product of CHO breakdown
• During digestion
• During fermentation
Sugars: Monosaccharides
• Galactose: almost never alone, usually
tied to gluc in lactose
Sugars: Disaccharides
• Maltose (Glucose + Glucose)
• Sucrose (Glucose + Fructose)
• Lactose (Glucose + Galactose)
Sugars: Disaccharides
• Sucrose: table sugar
• made from either sugar cane or sugar
beets
• Refined into brown, white, etc. sugars
2
Sugar & Health
CAN
CAN’T
• Aggravate BG
issues
• Have excess kcal
• Increase blood
triglycerides
• Cause dental caries
• Cause Diabetes
• Cause Hyperactivity
Sugars: Disaccharides
• Lactose: milk sugar
• the CHO source in breast milk
• Lactose --> glucose + galactose
• Requires enzyme lactase
• Shortage of lactase causes lactose
intolerance
Lactose Intolerance: Causes
•
•
•
•
•
•
Genetics
Medications
GI tract damage
Prolonged diarrhea
Low dairy intake: “Use it or lose it”
Common with aging
Sugar vs Honey
•
•
•
•
sugar = sucrose
honey = fructose + glucose + sucrose
More energy dense than table sugar
DO NOT feed to infants-botulism risk
Lactose Intolerance
• Not the same as milk allergy
• Undigested lactose molecules attract water
(osmosis)
• Sx: bloating, abdominal pain, diarrhea
AND
• Gut flora uses lactose as fuel
• Sx: gas, more bloating, more pain
Lactose Intolerance
• Tx is individualized
• Yogurt and cheese often ok-- bacteria
ferment the lactose during manufacturing
• Can replace lactase enzyme using "Lactaid"
tablets or drops.
• Or can use fortified soy milks.
3
Complex CHO
•
•
•
•
Complex CHO ≠ high fiber
Polysaccharides
Starch: plant storage form of CHO
Main sources: grains (wheat, corn, rice),
tubers (potatoes, yams), legumes
(beans, peas)
Glycemic Response
• How much a food affects BG
• Glycemic Index: ranking of foods p.116
• More than just the CHO affects GR!
CHO is a CHO is a CHO
• All CHO becomes glucose
BUT starch takes longer to digest than sugars
• Saliva & Pancreatic juice breaks down the
polysaccharides
• Intestinal juices breaks down disaccharides:
• maltase, sucrase, lactase
• monosaccharides go into the blood
• In liver, fructose and galactose get converted into
gluc
CHO: Brain’s favorite fuel
• Glucose is used to fuel the body’s cells
• Especially nervous system, RBC
• Extra is then stored…
• Better bet--stick to high fiber CHOs
Complex CHO
• Glycogen: animal (so OUR) storage form of
gluc, but not really found from food
• highly branched glucose chains--easy to
hydrolyse
• when gluc is plentiful (like after a meal) liver
turns the excess into glycogen
• Liver stores 1/3, for use when blood gluc
drops
Glycogen
• Stores only last for a few hours
• Glycogen “holds” onto water
• Early low carb diet success
• Only lasts a few hours
• Muscles store the other 2/3, but keep it for
their own work
4