Shared Flashcard Set

Details

Nutrition 1
Luke Nutrition Lectures...author:QC
45
Other
Professional
04/12/2010

Additional Other Flashcards

 


 

Cards

Term
essential aa's
Definition
His, Ile, Leu, Lys, Met, Phe, Thr, Trp, Val
Term
essential vitamins
Definition
Vit c, ADEK, Thiamin, Riboflavin, Niacin, B6, pantothenic acid, folic acid, biotin, B12
Term
essential minerals
Definition
calcium, phosphorus, magnesium, iron
Term
essential trace minerals
Definition
zinc, copper, manganese, iodine, selenium, molybdenum, chromium
Term
dietary reference intake (DRI)
Definition
aka RDA's
defined as intake meeting nutrient requirements in 97.5% of population of specific age and gender, i.e., 2 SD's above the mean requirment (high end of what's required)
Term
macronutrient energy sources
Definition
carbs (sugars & starches) 4 kcal/g
fats 9 kcal/g
**above: primary energy sources**

protein 4 kcal/g
alcohol-another NRG source 7 kcal/g
Term
kilocalories
Definition
used to measure energy content
1 cal= heat required to raise 1 gram water, 1 degree C)
Term
current recommendations for diets for healthy individuals
Definition
< 30% total kcal from fats
(< 10% sat, < 1% trans)

approx 15% from pt

rest from carbs (55%)
Term
Body composition relative to NRG for water and minerals
Definition
bulk of body wt, provide 0 NRG but essential
Term
body composition relative to NRG for carbs (glycogen)
Definition
small amount (0.2 kg)
small amount of NRG (900 kcal)
Term
body composition relative to NRG for protein
Definition
small amount (6 kg) but medium amount of NRG (24,000 kcal)
Term
relative body composition compared to NRG and availability for survival
Definition
Term
fuel utilization after 24 hour fast
Definition
muscle (pt) and adipose tissue degradation (2 primary sources)

(types of consumers) pure glucose to RBC/WBC's, FA's & ketones to heart, kidney, and muscle
Term
fuel utilization after 5-6 weeks starvation
Definition
BMR dec

body adapts with dec pt stores (due to inc pt metabolism), switch to ketoacid state (inc ketones in urine and ketone use by nervous tissue

inc urea due to high muscle breakdown
Term
Hypercatabolic (hypermetabolic) disease
Definition
due by injury, sepsis, infection results in inc metabolism, inc lipolysis, hyperglycemia, inc protein turnover & inc catabolism, inc body temperature

first metabolic insult, secondary PEM
Term
Stunting (growth failure)
Definition
due to chronic, mild PEM in early childhood; insufficient energy &/or protein to support growth of new tissues at normal rate; defined as height-for-age >2 SD below mean

adaptation to malnutrition
Term
underweight
Definition
result of acute mild PEM; defined in adults as BMI < 18.5

defined as weight-for-age >2 SD below mean (children)
Term
wasting
Definition
loss of body weight; sign of actue, severe PEM; defined as > 2 SD's below mean weight for height
Term
[image]
Definition
Unlike stunting, underweight and wasting are usually indicative of acute shortages of energy intake.
Term
kwashiorkor
Definition
primarily a dietary protein deficiency, often follows acute infection in weaning period (2nd/3rd years as breastfeeding is discontinued)

child typically btwn 60-80% expected wt
seen where primary foods are starchy roots (low pt diet)

edema due to hypoalbuminemia (40-50% of nml concentration)/impaired renal fct

skin changes: inc pigmentation, desqumation leading to hypopigmented areas and superficial lesions

fatty liver but no cirrhosis

hair dull, very fine, straight and sparse
lethargy, dec immunity
cardinal feature: banding of the ahir (signa de bandera), dark hair has alternating dark and light bands, corresponsing to periods of better and impaired nutrition
Term
marasmus
Definition
severe wasting int the young child (<60% expected wt) with marked loss of subQ fat and skm

poor prognosis for those >50% loss of body wt; child with severe disease has "old man" appearance, with sunken, wrinkled cheeks; no edema present
Term
catch up growth
Definition
btwn 2-5 yo (7-10 yo maximum upper limit)
Term
PEM epidemiology
Definition
developing countries: very high for those under age of 5

US: associated w/ hypermetabolic states (burn, infection); anorexia nervosa; chronic kidney disease/dialysis; elderly; poorly managed post-bariatric surgery
Term
PEM increases risk of death from concomitant infections
Definition
Term
treatment of PEM
Definition
1) resolve life-threatening conditions (ie fluid and electroylte disturbances/infections)

2) restore nutritional balance (ie slow introduction fo appropriate supplements)

3) ensure nutritional rehabilitation (ie slow introduction of traditional foods at appropriate levels)
Term
signs indicating poor prognosis in patients with PEM
Definition
1) age < 6 mths
2) deficit in weight for height > 40% or weight for age > 50%
3) signs of circulatory collapse: cold hands or feet, weak radial pulse, decreased consciousness
4) stupor, coma or other alterations in awareness
5) infections, particularly bronchopneumonia or measles
6) petechiae or hemorrhagic tendencies
7) dehydration and electrolyte disturbances, especially hypokalemia and severe acidosis
8)persistent tachycardia, signs of heart failure or respiratory difficulty
9) total serum pt < 30 g/L
10) severe anemia w clinical signs of hypoxia
11) clinical jaundice or elevated serum bilirubin
12) extensive exudative or exfoliated skin lesions, or deep decubitus ulcerations
13) hypoglycemia
14) hypothermia
Term
lipids and dietary fats
Definition
solubule in organic solvents (ie acetone, ether, or chloroform). Vary widely in size, polarity and function: hphobic TAGs and sterol esters to more water-soluble PL's. Dietary lipids includ cholesterol, phytosterols, TAGs (only NRG source).
Term
TAGs
Definition
majority of lipids consumed by humans (>95%)
composed of 3 fatty acids esterified to glycerol
FA's in dietary fats unbranched HC chains with even number of C's (due to synthesis from AcCoA), ranging from 4 to 26 carbons
very long chain FA's (> 22C) are the primary FA's found in brain tissue, as well as the retina and spermatozoa
adipose tissue (body fat) contains FA"s of varying lenghts
FA's vary with regard to the # of dbl bonds
Term
SFA (saturated FA's)
Definition
no dobule bonds
e.g., palmitic (C16:0), stearic (C18:0)
found primarily in animal & dairy fats, also palm and coconut oils

high SFA content = solid @ room T

associated w/ hyprecholesterolemia, recommended intake < 7% total kcals (most are atherogenic)

mechanism by which plasma cholesterol raised by SFA not clear b ut may dec catabolism of LDL
Term
MUFA's (mono-unsaturated FA's)
Definition
At least 12 C long, one double bond at n-7 or n-9 (NOT ESSENTIAL)

e.g., oleic acid (C18:1, n-9 cis)
high [ ] in olive and canola oils
NOT associated w/ inc plasma LDL or decreased HDL (neutral role)
Term
PUFA's (polyunsaturated FA's)
Definition
Multiple double bonds

Fatty acids with double bonds at n-3 or n-6 considered essential (enzymes can only insert dbl bonds @ n-9 or higher// do not have enzymes that add at n-3 or n-6).

essential FA's: linoleic and a-linoleic

omega 6 (n-6) omega 3 (n-3)

oils high in PUFA liquid @ room T

associated w/ lower plasma LDL (n-3 also dec HDL...overall lower total plasma cholesterol)
Term
essential FA's
Definition
Primary function – precursor of very long-chain fatty acids incorporated into cell membranes
Critical to maintaining fluidity of cell membranes
Term
essential FA's (names)
Definition
linoleic (C18:2, n-6, 9 all cis)
a-linoleic (C18:3, n-3, 6, 9 all cis)
Term
EFA deficiency
Definition
EFA deficiency rare in humans – if observed, due to n-6 deficiency
Can occur on very low fat diets (eg, Ornish); also in prematurity, long term TPN, after injury or sepsis, cystic fibrosis, multiple sclerosis
Signs: poor growth, scaly dermatitis (increased water loss due to changes in permeability), infertility, depressed immune reactions/inflamm responses, impaired platelet aggregation, kidney abnormalities, abn liver mitochondria, decreased capillary resistance, increased fragility of RBC's and reduced contractility of cardiac muscle

rare in humans, need for EFA supplementation in prematurity; deficiency also observed in cystif fibrosis, acrodermatitis enteropathica, peripheral vascular diseae and multiple sclerosis
Term
omega-3 fatty acids (n-3)
Definition
Absolute requirements not well established
Includes α-linolenic acid (essential), eicosapentaenoic acid (EPA) & docosahexaenoic acid (DHA)
Strong indications that n-3 fatty acids critical for neural and retinal tissue development
Have been shown to reduce CVD risk in people at high risk –
decrease risk of arrhythmias (sudden cardiac death)
decrease plasma triglyceride levels
decrease growth rate of atherosclerotic plaques
EPA & DHA from oily fish (mackeral, salmon, lake trout); α-linolenic acid from tofu, canola, walnut & flaxseed oils; some organic milks are supplemented with omega-3s

preterm infant may be vulnerable to n-3 deficiency b/c of immature desaturase and elongase enzyme activities and low fat stores
Term
trans fatty acids
Definition
rarely naturally occurring
hydrogenation turns liquid oils to solid fats – eg, vegetable oil to margarine (inc viscosity)– by reducing the rotational mobility of the fatty acyl chain via hydrogenation (liquids--> solid fats)
used in bakery goods – increased shelf life (decreases oxidation of fatty acids- rancidity) and flavor stability
associated with increased LDL levels, lower HDL CHD and atherosclerosis – to the same degree or more than saturated fats – mechanism not clear
Term
effect of FA commposition of cell membranes
Definition
1) high SFA & cholesterol--less fluid than membranes w/ high proportion of cis-PUFAs (esp omega-3,6)
2) FA's affect functioning of membrane proteins
3) dietary intake of FA's directly influences membrane composition
Term
mechanisms by which FA's affect functioning of membrane proteins
Definition
1) "fluid" environment enhances membrane-bound pt mobility
2) modification of fct by post-translational covalent bonding of lipid
3) FA's may be substrates for syntehsis of bioactive metabolites including eicosanoids and lipid peroxides
Term
Am Heart Assoc recommends less than 1% of total caloric intake from trans fat, currently the average is 2.6%
Definition
Term
impact of dietary/endogenous cholesterol on plasma cholesterol levels
Definition
dietary cholesterol has minimal impact on blood cholesterol levels

plasma cholesterol levels ARE influenced by dietary saturated fats, trans fats, fiber, alcohol
Term
[image]
Definition
oxidative stress (nml byprod of cellular and extracellular metabolic activity) induces lipid peroxidation of cell membranes

lipid oxidation occurs predominantly with PUFA

results: dec membrane fluidity, inc permeability to cations, loss of enzyme and receptor activity, impact membrane secretory activity

oxidation of membrane cholesterol produces oxysterols or cholesterol oxides, implicated in atherosclerosis

cellular lipid peroxidation depends on PUFA intake & intake of vit E an dother antioxidants
Term
dietary fiber
Definition
NOT an NRG source
plant polysacch & lignin resistant to hydrolysis by digestive enzymes

high fiber diets maintained for long term reduce the incidence of colon cancer; proposed mechanisms include bulking action of fiber speeds transit through the colon reducing absorption of advrse chemicals or that fiber adsorbs carcinogenic agents
Term
soluble fiber
Definition
H2O soluble
includes pectins and gusm (legumes & fruits)
implicated in cholesterol lowering
Term
mechanisms: dietary fiber lower cholesterol
Definition
1) bile-acid sequestering agent
2) reduce rate of insulin rise by slowing CHO absorption thereby slowing cholesterol synthesis
3) stimulate production of short-chain FA"s which are then absorbed by portal circulation and inhibit cholesterol synthesis
Term
insoluble fibers
Definition
cellulose and lignans (whoel grains & veggies); less impact on lowering cholesterol levels
Supporting users have an ad free experience!