Nutrition Flashcards
EAR / AR def
(USDA)
EAR = Estimated Avg Requirement
AR = Avg Req
-amt to meet requirements for 50% healthy ppl in a pop
RDA / RNI
(USDA)
= Rec’d Daily Allowance
= Rec’d Nutrient Intake (?derived from AR)
-avg daily amt to meet reqs of 97-98% of pop
AI
(USDA)
= adequate intake
*used when insufficient data for AR
-rec’d avg intake based on observed or experimentally-determined estimates in healthy pop
UL
(USDA)
= upper level of intake
highest daily amt likely to post no adverse effects to most ppl
Order of increasing intake
EAR / AR
RDA / RNI
RDA <– AI –> UL
AMDR and %’s
= Acceptable Macronutrient Distribution Range (% total cals)
P: 10-35%
C: 45-65
F: 20-35
Fat #’s
RDA / AI: (?infants only)
31 g/d in 0-6 mo
30 g/d in 7-12
AMDR:
30-40% in 1-3 yo
20-35% in 4+ yo (adults)
UL:
not defined (low sat fat)
EFA types (2)
-o6 (linoleic)
-o3 (a-linoleic –> EPA & DHA)
o6
-roles
-health benefits
-AHA
-roles:
clotting, CM in brain
-benefits:
↓ LDL
↓ infl
cardioprotective
possibly ↓ stroke
?benefits in CA, IBD, AI dz like RA
*AHA: 5-10% of E to ↓ risk CHD
o3
-eg
-roles
-health benefits
-AHA
-oils & some veg: ALA
-fish: EPA, DHA
(ALA can be partially converted to EPA or DHA)
o-6 to o-3 ratio
typical american diet 20:1
ideal may be 4:1
achieve by ↑ o-3 intake
Omega-3 PUFA #’s
(a-linoleic, fish oil, some veg, etc)
RDA / AI:
0.5-1.6 g/d
(men- 1.6, women 1.5)
AMDR:
0.6-1.2% (>1 yo)
… but AHA recs 5-10% to ↓ risk of CVD
UL:
not determined
Saturated fat, Trans fat, and Cholesterol #’s
RDA / AI:
Not defined!
AMDR:
Not defined!
UL:
“minimized”
*no required role
*AHA rec’s sub polys for sat fat ↓ risk of CVD 30%!
Carb #’s
EAR:
-100 g/d
RDA / AI: (?1o source of energy for brain)
-130 g/d
AMDR: (to maint wt)
45-65%
UL:
Not established
(sugars <25% E intake)
?
Preg: 175 g
Lact: 210 g
Are carbs essential
-Generally not essential!
…Except w some genetic defects in glucose metab
*No know carbohydrate deficiencies
Sugar limits
<25% total E intake (source?)
<50 g/d (12t)
Protein #’s
EAR:
.66 g/kg/d
RDA / AI:
56 g/d men
46 g/d women
AMDR:
10-35%
UL:
not defined!
Protein deficiencies
Kwashioror- protein only
Marasmus- pro & carbs
Protein and weight loss & maint
Loss:
1.2-1.5 g/kg daily
(about 90-120 lbs)
Maint:
0.7-1 g/kg daily
Fiber
38 g men (14-50y)
25 g women (19-50y)
(28 preg)
(29 lact)
Water AI
-includes all sources (food too)
-no RDA or UL
AI (L/d):
3.7 men ~1 gal
2.7 women
Vit D def & xs
def: osteomalacia (Rickets in kids)
xs: hyperCa+ complications
Vit D supp in babies
400 IU/d if breastfed only
Vit D def in obesity
-very common
-obesity causes vit D def bc diluted throughout body
Ca & obesity, effects on adipocytes
↑ Ca –> ↓ obesity
Adipocytes:
↓ PTH, vitD, intracellular Ca, lipogenesis, fat stores
↑ lipolysis
*opposite effects above with low Ca intake
Fe def
-common after bariatric surg, all need MVI to prevent
-ucytic anemia (MCV<80)
** serum ferritin most sensitive
GI sites of nutrient absorption
Stom: H2o, EtOH
Duod: Fe, Ca (FA, AA, other vits & mins)
Jeju: Fe, Ca proximally; also K, vits & min, carbs, AA, ?fats
Ileum: K, min, salts
**WATER
**FATS & vits ADEK
B12
& remain nutrients
bile salts & acids
Colon:
**WATER
Vit K
Biotin
B12
Thiamine
Riboflavin
NaCl
–> secretes K, HCO3
Most important parts of diet for wt loss
-LOW ENERGY
-ADHERENCE
LCD
-cals
-types
800-1500 cal/d
many types:
-exchange system/points
-portion controlled +/- MR
-low F
-low carb
-paleo, SB, Medit, etc
Low fat diet def (%)
<20% fat
??20-30% fat (AMDR 20-35)
55-65 carb
15 pro
<10% sat fat
↓ LDL & total chol
AHA recs & sat fat
?low fat diets only
-replace w polyuns veg oil ↓ CVD risk 30% (~statins!)
-if replaced w whole grain carbs ↓ CVD risk 9%
XXX do not replace with refined carbs (↑ CVD risk 1%)
Low carb diet def (%)
<45% (AMDR 45-65%)
Carbs: 50-150 g/d
-eliminate refined carbs
e.g. Zone, South beach, diabetic diet, VLCD
> =25% protein considered “high”
Ketogenic def
<50 g/d
Joslin new guidelines for T2DM
Low carb:
40% carbs (AMDR 45-65%)
-low GI, high fiber
20-30% protein
30% fat
-no trans
-7-10% sat
-20% mono & poly
VLCD
<800 cal/d
-MR plans typically:
-75-105 g protein
(1.5 g/kg IDEAL bw men)
(1.2 “ women)
-50-100g carbs
-10-20g fats (incl. EFA’s)
*can also be done w store-bought foods (PSMF)
VLCD’s more effective than LCD’s?
-VLCD’s did not produce greater weight losses than LCD’s
-MR plus LCD may be effective and less $ alternative
VLCD complications
GI: n/v/change in BMs
Cold intol
Dizziness
Fatigue
Derm: skin, hair, nail changes
Amenorrhea
Psych
Electrolytes: K, Na, cramps, arrhythmias
EFA def
Gout (pre-tx w allo)
Gallstones
Keto
Induction 20 g/d carbs
Maint 60-90 g/d
-20% protein
-75% fat
↓ HbA1c
-rapid weight loss
-may ↑ LDL, if ↑↑ possibly familial
Medit
35-40% fat = Moderate fat (AMDR 20-35%)
-high o-3, olive oil
-whole grains, fruits, veg, legumes
-fish, seafood
-limited poultry, rare red meat
-moderate EtOH
PREDIMED:
30% ↓ 1st CV event
40% ↓ onset of T2DM
50% ↓ recurrent CHD (Lyon)
Vegetarian diets
-protein sources
-vegan risks
-health benefits
-proteins: low-fat dairy, soy, legumes, whole grains, nuts, seeds
-vegans ↑ risk of deficiencies:
…B12, Fe, Zn, Ca, Vit D, o-3*
*may need to supp
…often in Lys as well
-health benefits of vegetarian diets:
…may ↓ CA risk (colon)
…cardioprotective
…↓ LDL
…↓ DM risk, ↑ glycemic control
MR
** best evidence for wt loss & MAINT
-loss: 2 MR/d better wt loss than diets w food
-maint: 1 MR/d
-can be used with any dietary approach
** partial MR plans produce ↑ wt loss vs. equivalent calorie diets
DASH diet
-↓ HTN, 8-14 pts in 2 wks
-not intended for wt loss
<1500 Na mg/d
whole grains
fruit & veg
dairy
lean meats, fish, poultry
nuts, seeds, legumes
E density
Dietary tx can also focus on low-E density foods like fruits & veg
-allows for ↑ volume & satiety
Diet effects on lipids
Wt loss in general:
↓ LDL and total chol
Low C (vs. low fat):
↓ TG & VLDL
↑ HDL
dz: ↓ DM2
Low fat:
↓ total chol
may ↓ LDL more than low carb
Health benefits of other diets
Med:
↓ CV mortality
↓ DM2
Veg:
↓ CV mortality
↓ DM2
also ↓ LDL
DASH:
↓ BP
VLCD:
↓ DM2
Low GI, High protein:
Weight maintenance
IF
-many different types
Study:
-IF w 70% calc EE
↓ wt, fat mass, LDL
… as compared to 70% red without fast
-if no E deficit, IF lost some weight but not improve health compared to other groups
Dietary effects on metabolism?
Resting EE decreases:
low fat > low GI > low carb
i.e. lower carb diets result in less metabolic slowing
*But POUNDS lost shows similar slowing across diets
Metabolic adaptation
> 10% wt loss leads to
↓ TDEE greater than expected from wt loss alone
…300-400 less calories to maintain body weight as someone who hasn’t lost 10% bw
-may last 6 mo - 7 yrs
(↑ muscle efficiency as well)
What is a calorie
1 _c_al = amt of heat to raise temp of 1 g of h2o by 1C
1 Cal = 1 kcal = 1000 calories
Essential AA
9(11): HILLMPTTV
His
Isoleu
Leu
Lys
*Meth & Cys
*Phenylala & Tyr
Threo
Trypto
Val
Conditonally essential AA’s
can convert to the other:
*Meth & Cys
*Phenylala & Tyr
RQ def & macros
-ratio Co2 produced : O2 burned (“C:Otient”), 20 min breath into tube
-unique to individ.
-used to calc BMR
Which macros metabolized:
0.7 fats
0.81 proteins / mixed diet
1.0 carbs*
*stupid mnemonic, high carbs = high co2
Micronutrient deficiencies after bariatric surgery (4)
Thiamine (B1)
Cyanocobalamin (B12)
Fe
Vit D
Thiamine (B1) def, sx & tx
-can become acutely deficient post-op, esp if lots of vomiting
Sx:
diplopia
nystagmus
facial weakness
polyneuropathy
ataxia
confusion
Wernicke’s encephalopathy (confusion, ophthalmoplegia, gait ataxia)
B_eriber_1:
wet- high output CHF
dry- symm polyneuropathy
Tx:
100 mg IV/IM QD x1-2wks
…then, 10 mg/d until recovered
Fe def
-p-bariatric surgery, all pts need MVI!
-routine monitoring to catch early (MCV <80)
-ferritin most sens test
Tx:
-oral replacement
-20-30% may need parenteral
B12 def causes (5)
- Pernicious anemia:
AI dz, gastric atrophy w ↓ IF - Gastric bypass:
-loss of parietal cells, ↓ IF
-30% @ 1 yr, 50% @ 5y if not suppl - Metformin:
–| ileum abs of B12
Tx: w Ca supp - Kids w obesity have 4x risk B12 def
- Vegans: inadequate B12 intake from animal products
Others:
-low intake of meat and dairy
-poor digestion of meats ↓ B12 release
-low acid e.g PPI
-low IF (as above)
B12 def sx
weakness / tired
palps
smooth tongue
angular cheilitis
change BM
nerves (numbness, gait, vision)
depression
memory loss
B12 dx
-B12 levels detect def but dont tell cause
-85% pern an have parietal cell abs, but IF abs less sens & more spec
-↑ MMA (bc B12 converts to succCoA)
-↑ homocysteine
Vit D def
-role
-def
-xs
-obesity
role:
-fight infxn, support healthy immune system
-bone formation, abs Ca
def:
-osteomalacia (Rickets in kids)
-post-bariatric bc ↓ Ca, vit D intake in food and ↓ absorption
…leads to 2o hyperPTH & osteoporosis
-exclusively breastfed babies need 400 IU/d
xs:
-rare, hyperCa & assoc complications
common in obesity:
-diluted
-↓ skin:volume ratio
-obesity causes vit D def, but NOT other way around
-30-40% prior to bariatric surg –> replace pre-op (50K u/wk x 2 mo)
-need to supp post-op & monitor q3mo, ?DEXA
Folic acid (B9) def
-causes (5 + 5 meds)
-sx
-dx
-tx
-aka pteroylglutamate / -ic acid
-suppl in preg to prevent neural tube defects
causes:
-unhealthy diets without fruit & veg
-abs probs: Crohn’s, celiac
-genetic do
-EtOH smoking
-MEDS: phenytoin, sulfasal, TMP-SMX, triamterene, OCP)
Sx:
-loss of app
-wt loss
-weakness
-sore tongue
-HA
-palps
-irrit
-macro, megalo anemia
Dx:
CBC, B12, folate (RBC folate leves better)
MMA nL w folate def (↑ w B12 def)
Biggest loser study @ 6 yrs
Metabolic adaptation:
-after 6 yrs, TEE increased but but remained below baseline
-those w ↑ persistent wt loss has ↑ metabolic slowing
-BUT those who regained also still had metabolic slowing ~500 cal
-physical activity maintained since competition
↓ leptin, T4, TG
↑ HDL, adiponectin
no change in ins sens
Estimating energy needs
- Need BMR:
-direct or indirect calorimetry
-calcuated - Maint cals = BMR x activity factor (1.2 sed - 1.9)
