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Carbohydrates
- composed of single or mutiple sugars
- carbon, hydroen, oxygen
- main fuel source for body
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Where do carbohydrates come from
photosynthesis
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Carbohydrates
- simple - Mono and disaccharides
- complex - oligosaccharides, polysaccharides and fiber
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simple carbohydrates
monosaccharides (single sugars)
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Monosaccharides (simple sugars)
- Glucose: "blood sugar," dextrose
- fructose: fruit sugar
- galactose
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Disaccharides
- simple sugars
- linked pairs of single sugars
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sucrose
- (glucose + fructose)
- table sugar
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lactose
- (galactose + glucose)
- milk products
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maltose
- (glucose +glucose)
- fermintation, alcohol products
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oligosaccharides
- 3-10 monosaccharides
- naturally in foods
- some foremed in gut
- cant be digested by human enzymes
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complex carbohydrates
polysaccharides
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starch
- stroage from of glucose in plants
- amylose and amylopectin
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glycogen
- storage for carbohydrates in humans
- similar to starch
- found in liver and muscle
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Glycogen
- liver glycogen ( 1/3 of glycogen)
- muscle glycogen (2/3 of glycogen)
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Dietary Fiber
- indigestible
- provide no energy
- insouluble fiber
- soluable finer
- pre- and pro-biotics
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insoulublue fibers
cellulose: whole grains, bran
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soluable fiber
pectin: fruit, oats
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Prebiotics
- substances that promote growth of bacteria
- origosaccharides
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probiotics
- living organisms
- health benefit
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beneficial effects
- promote feeling of fullness
- helps prevent constipation --> prevents diverticulosis
- reduces blood cholesterol level --> binds to cholesterol in small intestine; cholestrol cant be absorbed
- slows digestion and absorption of carbs
- may reduce risk of colon cancer
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Recommended dietary fiber intake
- adults = 25-38 g/day
- Dv = 25 g/day
- Avergae US intake = 14-17g/day
- best to obtain through diet
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carbohydrates needs
- RDA is 130 gram day for adults
- avearge US intake is 180-330g
- recomendations --> 45-65% of total calories should come from carbs
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Carbohydrates recommendations
- Whole-grains
- 50% of carbs intake should be in the form of whole grains
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Carbohydrate recomendations
- whole-grains
- 50% of carbs intake should be in the form of whole grains
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What is a whole grain?
- Made up of Bran, Gram, endosperm
- whole grain have all three
- refined grains hav bran and grem removed
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Sources of whole grains
- whole weat flour
- barley
- oatmeal
- brown rice
- popcorn
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recommendation for simple sugar intake
- low nutrient density
- added to food and beverages
- less than or equal to 10% of total Kcal/day
- avg. U.S. intake = 16% of total Kcal/day
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sweetners
- provide calories along with sweetness
- table sugar
- honey
- high fructose corn syrup
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High fructose corn syrup
- from corn
- use enzymes to convert glucose to fructose
- 55% of fructose is in soft drinks
- 42% of fructose in baked goods, desserts, etc.
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carbohydrate digestion
Goal: breakdown dietary carbohydrate into monosaccharides
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Digestion of carbohydrates in the mouth
- starch digestion begins
- salivary amylase
- short duration
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after absorption
absorped monosaccharides travel to the liver
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Liver can:
- release glucose into blodstream
- transform monosaccharides (galactose and fructose) into glucose
- stores as glycogen
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lactose maldigestion
- reduction in lactase
- severe causes are called lactose intolerance
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Reductioin in lactase
- lactose is undigested and not absorped
- lactose is metabolized by large intestinal bacteria
- causing gas, cramping, bloating, diarrhea
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Functions of carbohydrates
- supplies energy ( 4Kcal/g)
- protein sparring
- prevent ketosis
- sweetner
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What if we don't have enough carbohydrates in our diet?
- Need glucose to burn fat effeciently --> carbs prevent ketosis
- Body will use proteins to make glucose --> carbs have a protein sparing effect
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what happens ot blood glucose after a meal
increased blood glucsoe
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Blood goes into cells because
- cells need energy
- having a high blood glucose level causes diabetes
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Regulation of blood glucose
- hyperglycemia - high blood glucose
- hypoglycemia - low blood glucsoe
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body built in regulation system to ensure balanced blood sugar levels
- in hyperglycemia after meal
- in hypglycemia when meal is missed
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Role of pancreas
- release of insulin
- release of glucagon
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epinephrine
- "fight or flight response"
- breakdown glycogen
- reaises blood glucose
- advantage: the effects of epinephrine works alot faster than glucogen
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Diseases of blood Glucose Regulation
- Diabetes Mellitus (hyperglycemia)
- hypoglycemia
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Diabetes Mellitus
- disorders of carbohydrate metabolism
- charcterized by elevated blood glucose
- a disesase in which the body dose not produce or properly use insulin
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Type 1 Diabetes
- symtpons are more acute but treatable , you do not produce insulin
- usually found in children, use to be called juivenal diabetes
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Type 2 diabetes
- doesnt use insulin properly
- use to oly effect people in their 50's but now seen in people younger and younger
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Diabetes during pregnancy
Gestinatioal come while pregnant and after pregnancy it goes away
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Symptoms assocated with Diabtes
- fatigue
- frequent urination
- blured vision
- increased thirst
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Effects on the body
- Pancreas (type 1) - permanet damage because of diabates (blidness)
- Feet (circulation)
- wound healing problems
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Reasons for hunger constantly
needs energy for cells
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Reasons for fatigue
cells are starving and the breakdowin of fat will go up
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increased urination
diabetics are constantly thirsty because they have high blood sugar and the kidney dont filter
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Type 2
- most prominent
- 95 of all cases
- type 1-5%
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Diagnosis
- fasting blood glucsoe > 126 mg/dl
- normal = 70 -100mg/dl1
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Oral glucsoe tolerance test
- measure blood glucsoe over 2-3 hrs
- diabetes> 200mg/dl after 2 hours (normal <140 mg/dl)
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Glycemic index of foods
- blood glucose response of a given food
- influenced by various factors
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High Glycemic index
higher blood levels
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Low glycemic index
lower blood glucose levels
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Gestional diabetes
- pregnant women 4%
- usually occurs late in pregnancy
- hormones from placenta block the action of mothers insulin
- goes away after pregnancy
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