carbohydrates
class of nutrients that is a major source of energy for the body
monosaccharide
simple sugar that is the basic molecule of carbohydrates
glucose
monosaccharide that is a primary fuel for muscles and other cells; "blood sugar"
fructose
monosaccharide in fruits, honey, and certain veggies, "fruit sugar"
galactose
monosaccharide that is a component of lactose
disaccharide
simple sugar comprised of 2 monosaccharides
maltose
disaccharide composed of 2 glucose molecules; "malt sugar"
sucrose
disaccharide composed of a glucose and a fructose molecule; "table sugar"
lactose
disaccharide composed of a glucose and a galactose molecule; "milk sugar"
high- fructose corn syrup
syrup obtained from the processing of corn
nutritive sweeteners
substances that sweeten and contribute energy to foods
added sugars
sugars added to foods during processing or preparation
alternative sweeteners
substances that sweeten foods while providing few or no kcals
sugar alcohols
alternative sweeteners used to replace sucrose in some sugar- free foods; sorbitol, xylitol, mannitol
nonnutritive sweeteners
group of compounds that are intensely sweet tasting compared to sugar
complex carbs
carbs comprised of 3 or more monosaccharides bonded together
polysaccharides
carbs comprised of 10 or more monosaccharides bonded together
oligosaccharides
carbs comprised of 3-10 monosaccharides bonded together
raffinose
nondigestible oligosaccharide made of 3 monosaccharides
stachyose
nondigestible oligosaccharide made of 4 monosaccharides
starch
storage polysaccharide in plants; composed of amylose and amylopectin
glycogen
highly branched storage polysaccharide in animals
dietary fiber ("fiber")
nondigestible plant material; most types are polysaccharides
soluble fiber
forms of dietary fiber that dissolve or swell in water; include pectins, gums, mucilages, and some hemicelluloses
insoluble fiber
forms of dietary fiber that generally do not dissolve in water; include cellulose, hemicelluloses, and lignin
pancreatic amylase
enzyme secreted by the pancreas that breaks down starch into maltose molecules
maltase
enzyme that splits maltose into 2 glucose molecules
sucrase
enzyme that splits sucrose into glucose and fructose
lactose
enzyme that splits lactose into glucose and galactose
resistant starches
starches found in seeds, legumes, whole grains, and some fruits and veggies that resist digestion and are not broken down in the human GI tract
insulin
hormone secreted from the beta cells of the pancreas that contributes to a decrease in blood glucose levels
glucagon
hormone secreted from the alpha cells of the pancreas that contributes to an increase in blood glucose levels
lipolysis
process by which triglycerides (fats) are broken down into glycerol and fatty acid, which are released into the bloodstream
ketone bodies
molecules formed from the metabolism of fat that can be used as an alternative fuel for certain cells in the body when glucose levels are low
ketosis
adaptive metabolic state in which the body primarily uses fat for energy
ketoacidosis
condition in which ketone bodies accumulate in the blood; can result in loss of consciousness and death in severe cases
diabetes mellitus "diabetes"
group of serious, chronic conditions characterized by abnormal glucose, fat, and protein metabolism
hyperglycemia
abnormally elevated blood glucose levels
type 1 diabetes
autoimmune disease that results in destruction of the beat cells of the pancreas; as a result, insulin must be supplied to the affected person regularly through exogenous sources
type 2 diabetes
most common type of diabetes; beta cells of the pancreas produce insulin, but the hormone's target cells are insulin- resistant, leading to elevated blood glucose levels
gestational diabetes
type of diabetes that can develop during pregnancy
hemoglobin A1c (HbA1c)
glycated hemoglobin; blood test used to measure a person's average blood glucose over several month
carb counting
diabetes management tool in which an individual track his/ her daily carb intake
glycemic index (GI)
tool to measure the body's insulin response to a carb- containing food
glycemic load (GL)
tool to measure the body's insulin response to a carb- containing food; similar to the (GI), but also factors in the total carb content of a typical serving size of the food
hyperinsulinemia
condition in which the pancreas releases an excessive amount of insulin; over time, condition may contribute to development of type 2 diabetes
therapeutic lifestyle changes (TLC)
actions, such as avoiding excess body fat, exercising daily, and improving the diet, that promote health and reduce risk for chronic disease
hypoglycemia
condition that occurs when blood glucose level is too low
epinephrine (adrenaline)
hormone produced by adrenal glands; secreted in response to declining blood glucose levels
reactive hypoglycemia (postprandial hypoglycemia)
low blood glucose that occurs within 4 hours of eating
metabolic syndrome
condition that increases risk of type 2 diabetes and CVD
syndrome
group of signs and symptoms that occur together and indicate a specific health problem
lactose intolerance
inability to digest lactose properly because of a deficiency in the enzyme lactase
lipids
class of nutrients that do not dissolve in water; triglycerides, phospholipids, and sterols
fatty acid
hydrocarbon chain found in lipids; one end of the chain forms a carboxylic acid, one end forms a methyl group
hydrocarbon chain
chain of carbon atoms bonded to each other and hydrogen atoms
omega (methyl) end
end of a fatty acid containing a methyl (--- CH3) group
carboxylic acid
organic molecule with a carboxyl (--- COOH) group
saturated fatty acid (SFA)
fatty acid that has each carbon atoms within the chain filled with hydrogen atoms
unsaturated fatty acid
fatty acid that is missing hydrogen atoms and has one or more double bonds within the carbon chain
monounsaturated fatty acid (MUFA)
fatty acid that has one double bond within the carbon chain
polyunsaturated fatty acid (PUFA)
fatty acid that has 2 or more double bonds within the carbon chain
linoleic acid
18- carbon polyunsaturated fatty acid with 2 double bonds; an essential fatty acid
alpha- linolenic acid
18- carbon polyunsaturated fatty acid with 3 double bonds; an essential fatty acid
omega- 3 fatty acid
type of polyunsaturated fatty acid with the first double bond at the third carbon from the omega end of the molecule
omega- 6 fatty acid
type of polyunsaturated fatty acid with the first double bond at the 6th carbon from the omega end of the molecule
essential fatty acids
fatty acids that must be supplied by the diet; ex: linoleic and alphalinolenic acid
arachidonic acid (AA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA)
essential fatty acids; precursors to some eicosanoids
eicosanoids
group of long- chain fatty acids with hormonelike functions
prostaglandins
class of eicosanoids that produce a variety of important effects on the body
trans fats
unsaturated fatty acids that have a trans double bond
partial hydrogenation
food manufacturing process that adds hydrogen atoms to liquid vegetable oil, forming trans fats
triglyceride
liquid that has 3 fatty acids attached to a three- carbon compound called glycerol
glycerol
three- carbon alcohol that forms the "backbone" of fatty acids
monoglyceride
liquid that has one fatty acid attached to a three- carbon compound called glycerol
diglyceride
liquid that has 2 fatty acids attached to a three- carbon compound called glycerol
phospholipid
type of liquid needed to make cell membranes and for proper functioning of nerve cells; chemically similar to a triglyceride, except that one of the fatty acids is replaced by a chemical group that contains phosphorus
hydrophilic
part of a molecule that attracts water
hydrophobic
part of a molecule that avoids water and attracts lipids
emulsifier
substance that helps water- soluble and water- insoluble compounds mix with each other
choline
water- soluble, vitamin- like compound; component of lecithin
cholesterol
liquid found in animal foods; precursor for steroid hormones, bile, and vitamin D
sterols
type of liquid that has a more complex chemical structure than triglycerides and phospholipids
plant sterols/ stanols
chemicals found in plants that are structurally similar to cholesterol
lipases
enzymes that break down lipids
pancreatic lipase
digestive enzyme that removes 2 fatty acids from each triglyceride molecule
bile salts
component of bile; aid in lipid digestion
micelle
water- soluble, spherical lipid cluster; bile salts create a shell around each cluster, allowing for the structure to be suspended in watery digestive juices
fat malabsorption
impaired fat absorption; symptoms include diarrhea, fatty stools, rapid weight loss
chylomicron
type of lipoprotein formed in enterocytes to transport lipids away from the GI tract
lipoproteins
water- soluble structures that transport lipids through the bloodstream
lipoprotein lipase (LPL)
enzyme in capillary walls that break down triglycerides
very low- density lipoprotein (VLDL)
lipoprotein made in the liver; carries much of the triglycerides in the bloodstream
low- density lipoprotein (LDL)
lipoprotein that carries cholesterol into tissues; elevated (LDL) is linked to increased risk of CVD
high- density lipoprotein (HDL)
lipoprotein that transports cholesterol away from tissues and to the liver, where it can be eliminated; low (HDL) is linked to increased risk for CVD
enterohepatic circulation
process that recycles bile salts in the body
gallstones
hard particles that can accumulate in the gallbladder or become lodged in one of the ducts carrying bile from the gallbladder to the small intestine
cholecystectomy
surgery to remove a diseased gallbladder
steatorrhea
presence of lipid in the stool
gaucher disease
most common lipid storage disease; caused by a deficiency of an enzyme involved in lipid metabolism