Nutrition Flashcards
kcal/g of: protein, carbohydrate, fats, EtOH
Protein: 4
carbohydrate: 4
fats: 9
EtOH: 7
What is the percent energy expenditure of: physical activity, thermic effect of digesting food, resting energed expenditure/basal metabolic rate?
Physical activity: ~20-30%
Thermic effect of food: ~10%
BMR: ~60-70%
What are healthy levels of body fat in men and women?
2-20% in men, 20-35% in women
In which conditions are decreases in BMR per kg of lean-mass seen?
Hypothyroidism, anorexia nervosa, down syndrome, very-low-calorie diets, starvation states
In which conditions are increases in BMR per kg of lean-mass seen?
Hyperthyroidism, Parkinson’s disease, asthma, hypermetabolic state (burns, sepsis)
What happens to BMR during severe caloric restriction? Results of the Minnesota study?
BMR decreases with calorie restriction before mass is lost, and increases with feeding before mass increases
Fuel utilization in 24 hour fasting vs 5-6 weeks of semi-starvation?
Mostly muscle and adipose tissues are mobilized in the first 24 hours. After 5-6 weeks, muscle utilization drops waaaay down to preserve muscle, adipose tissue utilization continues, BMR drops
What happens with chronic but mild Protein Energy Malnutrition (PEM) and how is that condition defined?
Stunting, defined as >2 std deviations below mean for height average.
Acute, mild PEM results in what condition? How is that condition defined?
Underweight, defined as BMI <18.5 in adults
Acute, severe PEM results in what condition(s)? How are these conditions defined?
Marasmus, defined as <60% expected weight with marked loss of subq fat and skeletal muscle
Kwashiorkor, defined as 60-80% below expected weight, edema, impaired renal function, fatty liver, skin and hair color changes
What type of fats are associated with hypercholesterolemia? Which not associated with either higher or lower LDL/HDL? Which associated with lower LDL?
Saturated fats, MUFA, PUFA
What are the essential fatty acids and why are they important?
linoleic acid (omega 6), and alpha-linolenic acid (omega 3), act as precursors for long chain fatty acids required for cell membranes, especially linoleic acid
What do trans fats do the LDL and HDL?
Raise LDL and lower HDL. So, the opposite of good.
Clinical sx of Essential Fatty Acid deficiency? Name 5. There’s like 50.
reduced growth rates, scaly dermatitis with increases water loss, male and female infertility, depressed inflammatory responses, kidney abnormalities, abnormal liver mitochondria, decrease capillary resistance, increased fragility of erythrocytes, and reduced contractility of cardiac muscle
How does fiber lower cholesterol? Which type of fiber (soluble or insoluble) does this better?
Sequesters bile acid, slows carbohydrate absorption rate = lowering insulin rise rate and cholesterol synth rate, stimulates production of short-chain fatty acids which inhibit cholesterol synthesis. Soluble does it better.
Which vitamins are fat soluble?
FAKED - Fat soluble A, K, E, and D
Other name for Vitamin A?
Retinol
Function of Vitamin A
Important in vision, cell differentiation including epithelial cells, and immune responses
Vitamin A deficiency sx
Night blindness early, epithelial keratinization, early conjunctival dryness (xerosis), Bitot’s spots (dry, fatty deposits), Keratomalacia (thick white opacities on the cornea which cause blindness)
Vitamin A toxicity
Acute: N/V and HA, peeling of skin
Other name for Vitamin D?
Cholecalciferol
Function of Vitamin D
Maintain serum calcium and phosphorus concentrations by increasing intestinal absorption, renal reabsorption, and bone resorption. May also play role in gene expression regulation
Vitamin D deficiency sx
Rickets in children (causing bowed legs), osteomalacia in adults
Other name for vitamin E?
Tocopherols
Function of vitamin E
antioxidant in cell membranes, especially PUFA’s in phospholipids of membranes and plasma lipoproteins
Vitamin E deficiency sx/dz?
Usually due to genetic mutation, almost never due to dietary deficiency. Causes neurological abnormalities with progressive peripheral neuropathy, ataxia
Other name for vitamin K?
Phylloquinone
Function of vitamin K?
Co-factor for proteins involved in coagulation and bone-associated proteins
Vitamin K deficiency sz/dz?
Bleeding, poor coagulation. Most common in breast-fed newborns, can see hemorrhagic dz in newborns.
Vitamin B1, aka…?
Thiamin
Function of Thiamin
coenzyme with Transketolase (pentose phosphate pathway), pyruvate dehydrogenase, and alpha-ketoglutarate dehydrogenase
Thiamin deficiency sx?
Seen in breast-fed infants of deficient mothers, adults with high carb intake, and chronic alcoholics. Causes Beriberi
Dry Beriberi: peripheral neuropathy, impaired sensorimotor
Wet Beriberi: CHF, tachycardia, edema, cardiomegaly
Cerebral beriberi: confusion, aphonia, nystagmus, which may progress to Wernicke’s Encephalopathy: spongy degeneration of the mamillary body
Infantile beriberi: aphonia, polyneuropathy, and cardiac failure
Vitamin B2, aka…?
Riboflavin
Function of riboflavin
redox coenzyme in succinate dehydrogenase (CAC), and acyl CoA dehydrogenase (beta-oxidation)
Riboflavin deficiency sx?
Relatively non-specific sx, rarely occurs alone, usually in concert with other B-vitamin deficiencies. Include sore throat, cheilosis, angular stomatitis, glossitis, seborrheic dermatitis
Function of Niacin
Act as coenzymes with NAD/NADP for redox rxns, ATP synth, and ADP-ribose transfer rxns. Can be manufactured in the body from tryptophan
Niacin deficiency sx/dz?
Pellegra, 4 D’s: diarrhea, dermatosis, dementia, death
Folic acid function
Coenzyme in thymidylate synthetaase, which makes dUMP to dTMP which is necessary for DNA synthesis
B12 function
Coenzyme for methionine synthase aka homocysteine methyl-transferase and methylmalonyl-CoA mutase
B12 aka..?
Cobalamin
Interdependence of folic acid and B12
Folic acid aka THF (tetrahydrofolate) needs to be demethylated after being reduced to methylene THF, which solely exists to methylate homocysteine to methionine. Without B12 to coenzyme Methionine Synthetase, THF could not be regenerated
Folic acid deficiency sx/dz?
megaloblastic anemia (causes weakness, dyspnea, sore tongue, anorexia, HA), anemia, leucopenia, thrombopenia,
B12 deficiency sx/dz?
Pernicious anemia due to lack of intrinsic factor, impaired nucleic acid synth, increase in plasma homocysteine which is associated with CVD.
Vitamin C aka?
Ascorbic Acid
Function of Vitamin C?
Coenzyme for rxns requiring reduced metal ion, essential for cross-linking of collagen, enhances intestinal absorption of iron
Vitamin C deficiency sx/dz?
Scurvy. Sx: defects in connective tissue formation, hemorrhagic bleeding into joints, peritoneal cavity, and pericardial sac, inflammation/bleeding of gums
Calcium function
Provides bone/teeth structure, activates catalytic cellular proteins, stabilizes blood clotting enzymes, intracellular messenger
Calcium deficiency sx/dz?
Associated with osteoporosis in adults, rickets in infants
Function of Phosphorus
Major component of hydroxyapatite in bone, important in cell membrane phospholipids, all enzymes, 2nd messenger systems, acid-base balance
Phosphorus deficiency sx/dz?
Refeeding syndrome: severe hyperglycemia, weakness, muscle paralysis, cardiorespiratory failure, and death
Function of iron
Iron-sulfur complexes: part of mitochondrial aconitase which converts citrate to isocitrate in CAC, critical in oxidative phosphorylation
Heme-iron: carries O2, constituent of peroxidase enzymes, active site of cytochrome in ETC
Iron deficiency sx
Microcytic hypochromic anemia (small RBC’s): fatigue, lightheadedness, dyspnea on exertion, pallor
Function of zinc
zinc finger motifs, polymerization of tubulin
Zinc deficiency sx/dz
Subclinical sx: impaired growth, immune system problems
severe sx: delayed sexual maturation, hypogonadism, hypospermia
Function of Iodine
Essential in thyroid hormones for growth/development
Iodine deficiency sx/dz
Goiter, lethargy, sleepiness, cold intolerance, weight gain. Especially damaging during periods of rapid growth
