carbohydrates
causes of lactose intolerance
-age -damaged intestinal villi due to: disease, medicines, prolonged diarrhea, malnutrition --> can be permanent or temporary
too much fiber
-insufficient energy/nutrient needs -abdominal pain, gas, diarrhea -GI obstruction -nutrient absorption
Type 2
-most cases 90-95% -insulin resistance: insulin is not working like it should, hyperinsulinemia, insulin deficiency
phytic acid
-not a dietary fiber -found in the same foods as fibers/high fiber foods -possible mineral deficiency linked to binding, preventing absorption
carbohydrate digestion
-very little occurs in mouth -basically put on hold in stomach, acid inactivates enzymes -enzymes to digest CHO come from pancreas: pancreatic amylase -most carb digestion takes place in small intestine, with help of pancreatic amylase: poly & disachs are broken down into monosacharides
abundance of glucose
1. fat is conserved - body uses all the glucose that is available before using fat for fuel, tries to use up glucose before it is stored as fat 2. fat is created -> too much glucose, liver will break down the extra and turn it to fat
how much added sugars to americans consume daily
30 tsps DRI for sugar is no more than 25% of day's total energy -- other recommendations are even lower
recommended intakes for starch & fibers
CARBS: -DRI: 45-65% of energy requirement should come from carbs -RDA: 130 grams per day of carbs Fiber: -DV: 11.5 grams per 1000 kcals (25 g) -DRI: 14 grams per 1000kcal (25-35 g) No upper limit
who is most tolerant / intolerant to lactose
Genetically, highest intolerance --> lowest: -asians & native americans -african americans most tolerant: Caucasians and northern europeans
hydrolysis reaction
H20 splits, breaking a disaccharide in two using water --> *breaking something down*
glucose
a monosaccharide that provides nearly all brain energy. a part of every disaccharide, this is energy that keeps you running. **blood sugar** -preferred energy source for brain, nerve cells & developing red blood cells
insulin deficiency
amount of insulin is insufficient to compensate for diminished effects inc ells
Hypoglycemia
blood glucose drops below normal: weakness, sweating, hunger, anxiety, trembling. (very rare) How to help: replaced refined (processed) CHO, increase fiber, add protein w/ meals, smaller frequent meals
other lactose sources (besides dairy)
breads, cereals, breakfast drinks, salad dressings, cake mix, milk solids, whey, casein, medications
disaccharides
composed of *pairs of monosaccharides* -- one of the pairs is always glucose. -maltose, lactose, sucrose
Gluconeogenesis
conversion of a non CHO source (protein/fat) to glucose -> fat can't be significantly converted to glucose, and protein has more important roles
functional fibers
dietary fibers extracted from plants or manufactured, then *ADDED to foods in supplements* -> often a powder or something you take a supplement for people who need more fiber
resistant starches
dietary fibers which escape digestion & absorption in the small intestine **support healthy colon** -->sources: whole/partially milled grains, legumes, just ripened bananas, potatoes, pasta, rice
insoluble fibers
don't dissolve in water or form gels, and are less fermented than soluble fibers *promote regular bowel movements, alleviate constipation, prevent diverticular disease*. -->sources: whole grains, bran & veggies
soluble fibers
easily digested by bacteria in the colon; forms gels *protect against heart disease & diabetes* --> sources: oats, barley, legumes, citrus fruits
large intestine role in digestion
fibers attract water and this softens stool -bacteria ferment some fiber; short chain fatty acids can be used by the colon for energy
sucrose
fructose + glucose --> table sugar (disaccharide)
lactose
galactose + glucose (disaccharide) ex: milk sugar
maltose
glucose + glucose (disaccharide) ex: barley
glucagon & epinephrine
hormone secreted by the pancreas and adrenal glands, respectively -will increase blood sugar when levels drop and will bring glucose from storage
insulin
hormone secreted by the pancreas that is used to decrease blood sugar
glycemic response
how quickly glucose is absorbed after meals, how high blood glucose rises & how quickly it returns to normal ** desirable for this to be slow
glycogen
is converted from glucose and stored in muscles... provides about half of all energy the muscles and body tissues use (other half is from fat) -not a dietary CHO -STORAGE form of CHO in animals -stored in muscle and liver
ketosis
ketone production exceeds its use, and accumulates in blood, disturbing the pH balance --> ketones are formed as an alternate energy source from fats in starvation state
polysaccharides
large molecules composed of chains of monosach. -- *long chains of glucose* -starch (plant), glycogen (animal), fibers
condensation
makes a disaccharide + H20 -links two monosaccharides together; basically *building* a molecule
end product of carb digestion
monosaccharides
blood glucose ranges
normal: 70-100 mg/dl prediabetes: 100-125 mg/dl diabetes >= 126 mg/dl
lactose intolerance
not enough lactase enzyme leads to lactose molecules not being digested --> attracts water --> bloating, gas, diarrhea, etc. -GI bacteria activity can improve symptoms
type 2 diabetes causes
obesity, poor diet, smoking, aging, inactivity, ETOH (?)
monosaccharides
one C-H-O -*glucose*, galactose (in few foods), fructose (very sweet: fruit, honey)
symptoms of type 1
polyphagia - hunger & excessive eating polyuria - frequent urination polydipsia - excessive thirst ketones in blood, urine, breath
protein sparing (PS) action
providing energy that allows protein to be used for its main purposes -- basically eating enough CHO so that you can use it to convert into glucose -->50-100 g of CHO/day are needed
active transport
requires energy & a carrier protein -glucose & galactose
facilitated diffusion
requires only a carrier protein -fructose
Total carbohydrates on food labels includes:
starch, fibers, sugars
starch
storage form of energy in *plants*, many glucose units (polysaccharide)
Liver storing glucose as glycogen
stores about 1/3 of glycogen -after meals, increase in blood sugar -> condensation: linking excess glucose into glycogen -between meals: decrease in blood sugar -->hydrolysis: breakdown of glycogen for release of glucose when needed for energy
muscle storing glycogen
stores about 2/3 of glycogen -once it is in the muscle, it stays there (won't go to other organs even if needed) -there is more muscle content in the body, so muscle stores more than the liver
fibers
structure part of plant, different from starches because the bond between monosacharides can't be broken down by digestive enzymes -- many types of fibers **role: lingers, delaying gastric emptying, making you feel fuller longer
how long does glucose last?
supplies of glucose last about 1/2 day when we're resting, and only a few hours with activity
hyperinsulinemia
too much insulin is in the blood (bc pancreas is still making insulin, but cells aren't able to take it up
symptoms/signs of type 2
weight GAIN -polyphagia, polyuria, polydipsia
liver
when blood circulates into the liver from small intestine, liver takes up & converts fructose & galactose --> into glucose so the body can use it.
diabetes
when blood glucose rises after a meal, it remains above normal -insulin is either inadequate or ineffective -6th leading cause of death, autoimmune disease (our body destroys insulin and the pancreatic cells that produce it)
sources of carbs
whole grains, vegetables, legumes, fruits, milk/milk products