Nutrition Flashcards
Nutrition
The process of acquiring nutrients to support energy & cellular processes.
RD vs CDN vs Certified Nutritionists
RD is nationally board cert. by Comm. on Dietetic Reg.
CDN/LDN is state specific
CNS only by board for CNS
*Only RD/LD can prescribe meal plans
Micronutrients
Vitamins: organic
Minerals: inorganic, major & trace amt.
Phytonutrients: plant based
*Don’t provide energy but have important regulatory functions in the metabolic pathway
Protein
Synthesizes & repairs cells, tissues, and structures, such as collagen, elastin & muscle
Required for synthesis of hormones & transport of lipids & minerals
Amino acid (C-H-O-N) linked by peptide bonds in polypeptide chains. They are the building blocks that synth & repair protein.
9 essential, 20 non-essential
Protein turnover
The breakdown of internal proteins and recycling of the amino acids for synthesis of new proteins.
Name Essential Aminos & concept of Conditionally Essential
Histidine
Lysine
Leucine
Isoleucine
Theronine
Tryptophan
Phenylalanine
Methionine
Valine
Certain non-essentials may become conditionally essential under heavy workload or metabolic stress
Complete vs Incomplete Protein
Complete: Provides all EAA. Animal, Soy & Hemp (incl quinoa & buckwheat)
Incomplete: Lacks one or more EAA. Legumes, grains & Veg.
The 4 Protein Structures
Primary
Peptide chain: simple linear
Secondary: Helix shape
Tertiary: 3d Coil shape polypeptide chain
Quaternary: Assembled coils
Mutual supplementation
Combination of two incomplete protein sources, that will together provide all EAA.
Protein quality & Low Biological Value Proteins (LBV)
Quality: Contains all EAA & easily digestible
LBV: Lacking one or more EAA
Protein Assessment
Protein efficiency ratio (PER)
Biological Value (BV)
Protein-digestability-corrected AA score
(PDCAAS)
Net Protein Utilization (NPU)
PER: assessing value of protein based on weight gain divided by ingested protein
BV: a reference amt. measures digestibility & absorption of AA by a specific protein
PDCASS: compares AA in a food source to a standard AA profile & assesses
digestibility w/ top score 1.0
NPU: ratio of AA mass actually turned into proteins, compared w/ total AA mass consumed
Digestion steps of Protein
Saliva enzymes do little to digest proteins
Protein is consumed and enters the stomach where hydrochloric acid DENATURES it, meaning that the secondary & tertiary structures are unraveled to expose the primary structure (peptide chains)
Continuing in the stomach, digestive enzymes (Pepsin) clip the exposed peptide bonds, making di- or tri-peptides.
The small intestines continues the breakdown w/ protease enzymes reducing the now smaller remaining peptide chain into single AAs & di-peptides, which can be absorbed into the body.
Meanwhile, some AAs enter the intestinal wall & enterocyte (intestinal cell) ie-Glutamine
AAs are delivered into the liver through the portal vein & circulated into the bloodstream.
Using Protein for Energy: Deamination & Gluconeogenesis
Deamination: Occurs when excess protein is present. Nitrogen is removed and excreted in urea. Remaining Carb-Hydr-Oxyl are metabolized to meet energy demand.
Gluconeogenesis: Oxidation of AAs glutamine & alanine to synth glucose.
RDA of Protein
0.8g per kg to maintain nitrogen bal.
Accepted Macronutrient Distribution Range (AMDR)
National Academy of Medicine rec’d for 97-98% of population, associated w/ reduced risk of chronic disease.
Symptoms of excessive protein intake >2.2g per kg
GI distress
Excretion of Ca
Kidney stones
Carbohydrate
Like protein, it yields 4 cals per gram.
Contains C-H-O atoms.
Structures of Carbohydrates: The two simple sugars
Monosaccharides: Simplest. Single unit of sugar. Glucose (fruit and simple syrup); Fructose (fruit and the sucrose in table sugar) & Galactose (milk and dairy).
Disaccharides: Two monosaccharides joined together. Lactose (glucose & galactose); Sucrose (glucose & fructose) & Maltose (glucose & glucose).
Structures of Carbohydrates: Polysaccharides
Long chains of glucose that a joined together to form the structures for Starch (storage form of Carbs in plants); Glycogen (storage in liver & muscles) & Fiber (indigestible carbs in plants)
Fiber reco: women & men 19-50 yrs. 25 & 30g.
Fiber types
Soluble:
Oats; Most fruits & veg.
Lower cholesterol
Delays gastric emptying
Insoluble:
Whole grains, nuts, lentils, potatoes
Most fruit & veg outer skin
Adds bulk, satiety
Improves regularity
Carbohydrate digestion: Mono & Disaccharides vs Polysaccharides
Mono & Disaccharides can be digested easily thru intestinal lining.
Polysaccharides must be broken down by enzymes into Mono or Disaccharides. They then travel to liver, which converts most fructose & galactose into glucose.
Complex Carbohydrates
Polysaccharides, which are long chains of simple sugars (whole grains, legumes & veg).
Slower rise in glucose levels.
Glycemic Index & Glycemic Load
GI: How quickly a carb will raise glucose levels when consumed solo. Glucose is given value of 100.
GL: Factors in the GI of a food with the amount of that food that is consumed.
Carbohydrate intake recommendations
AMDR: 45-65% of cals (130g in 2000 cal)
Light exe: 3-5g/kg
Mod: 5-7g/kg
High: 8-12g/kg
Carbohydrates as fuel: HITT vs sub-V1
Carbs are broken down into glucose, which is immediately oxidized for HITT efforts
During longer sub V1 efforts, muscle glycogen provides approx HALF the fuel needed. FFA make up rest.
Lipids
9 cals per gram
Categorized into: Triglycerides, Phospholipids & Sterols.
Triglycerides: Def & Str.
The substrate form of most Fats in food & the body.
Glycerol backbone w/ 3 fatty acid chains
Found in solid fats & oils
Phospholipids: Def & Str
Important component of cell membrane
Glycerol backbone w/ 2 fatty acid chains & a phosphate molecule.
Found in egg yolks, lean meat & fish, soybeans, grains & seeds
Sterols: Def & Str
Ringlike str of carbon and hydrogen atoms
Precursor to many hormones & also part of cell membrane
Found in dietary cholesterol, self synth cholesterol & plant sterols.
Saturated vs Unsaturated Fats: Str.
Saturated fatty acid chains have NO DOUBLE BONDS.
Usually solid at room temp & safe in moderation.
Unsaturated fatty acid chains have one or more double bonds. Double bonds are known as points of unsaturation.
Monounsaturated Fats: Def. & Str
An unsaturated fat w/ only 1 point of unsaturation (double bond).
Heart healthy; Mediterranean diet
Olive oil, canola oil, avocado & peanuts
Polyunsaturated Fats: Def. & Str
An unsaturated fats with two or more points of unsaturation (double bonds)
Omega 3 (epa/dha): Heart healthy, improved LDL, improve cognitive fx.
Found in fish oil & seeds & some dairy
Omega 6: Growth & dev.
Found in nuts & seeds
*Ideal ratio 4:1 omega 6 to 3
Trans Fats: Def.
Artificial & added natural trans fats. are in food w/ partially hydrogenated oils.
Incr LDL & lower HDL
Naturally occurring in animal fats are less harmful
Lipid Digestion: Steps
Small amount digested in mouth by the saliva enzyme, lingual lipases.
Minimal digestion in stomach.
Most digestion occurs in the small intestines where pancreatic enzymes (lipases) breakup long chain fatty acids into monoglycerides & FFAs for absorption into enterocytes.
Enterocytes repackage FFAs w/ other fat soluble nutrients (vitamins), triglycerides, phospholipids, cholesterol & protein into CHYLOMICROMS & send them to the liver.
The liver redistributes triglycerides as lipoproteins LDL to body tissues, where the enzyme lipoprotein lipase (LPL) cuts up the triglyceride component to release FFAs.
The FFAs are taken up by cells in muscles, organs, and adipose tissue & are either stored or metabolized for energy depending on the body’s need.
Lipid digestion: Sketch it
Include:
Lingual lipases
Pancreatic enzymes
Lipase
Chylomicrons
Lipoprotein (LDL)
Triglycerides
Lipoprotein Lipase
Destination of FFAs
Lipid dietary needs by %
AMDR suggests 20-30%
Sat fat limited to 10% or less
Mono/Polys up to 25%
Important source of metabolites. Omega 3s & 6s are essential
Dietary cholesterol and its effect on serum cholesterol
For most healthy individuals dietary cholesterol has little effect on serum cholesterol.
All vitamins & minerals are essential, except for:
Vitamin D
Niacin
Biotin
Fat-soluble vs Water-soluble Vitamins
Fat-soluble: Requires Fat for digestion. Travels through lymphatic system and circulates w/ other fat-soluble nutrients to the liver, where they are repackaged (into Clyomicrons) with lipoproteins & redistributed to other organs and tissues. Can be stored in liver and adipose & not needed daily.
Vitamins: A-D-E-K
A: vision; orange & green veg. Egg yolk
D: calcium absorp, parathyroid, fatty fish
E: antiox; nuts
K: blood clot & bone health; dark greens
Water-soluble: Absorbed directly into blood stream. Not transported in chylomicrons.
C: antiox, collagen; fruit & veg OJ
B series:
B1-thiamin: energy met, beri beri; meats
& fort cereal
B2-riboflavin: energy met, cheilosis; dairy, meats & fort cereal
B3-niacin: energy met, pellagra; above plus beans
B4-pyridoxine: energy met, deamination & transamination of protein, converts tryptophan to niacin.
B9-folate: dna/rna synth, rbc synth, neural tube defects, cancer prevention; dark greens, OJ
B12-cobalamin: energy met, dna/rna, nerve signals; methylation; most food
B5-pantothenic acid: energy met; most food
Vitamin C benefits
Collagen synth & antioxidant activity.
Shortage leads to scurvy.
B vitamins involved in RBC synth
B5- folate
B6- pyridoxine
B12- cobalamine
Deficiencies lead to anemia
B vitamins mainly involved in energy metabolism
B1-Thamin
B2- Riboflavin
B3- Niacin
B7- Biotin
B5- Pantothenic acid
B6- Pyridoxine
B12- Cobalamin
Derivatives & metabolites of the above facilitate ATP production from carbs and amino acids.
Deficiencies cause lethargy & confusion & compromised athletic performance.
Major minerals
Minerals are found in plant & animal foods.
Present in a larger quantity in the body & are required in larger amounts.
Calcium
Potassium
Magnesium
Sodium
Chloride
Sulfur
Major minerals
Minerals are found in plant & animal foods.
Present in a larger quantity in the body & are required in larger amounts.
Calcium (most abundant)
Phosphorous (also most)
Potassium
Magnesium
Sodium
Chloride
Sulfur
Trace minerals
Iron
Zinc
Copper
Manganese
Chromium
Fluoride
Molybdenum
Recommended fluid intake
Men: 15.5 cups/ 124 oz.
Women: 11.5 cups/ 92 oz.
Replenish water after exercise to
what %?
125%
Sports drinks: hypotonic; isotonic; hypertonic
Hypotonic: less electrolytes & salt
Isotonic: same electrolytes & salt as in body
Hypertonic: more electrolytes & salt. Absorbed fastest. least common drink. Can cause GI distress.
Sleep deprivation and its effect on hormones
Peptide YY, the satiety hormone, is lowered.
Ghrelin, the hunger hormone, is increased.
Hypothyroidism
Hormone disorder causing: Low activity in the thyroid, contributing to slower metabolism.
Cushing’s syndrome
Hormone disorder causing: Excessive amount of cortisol in the body
Polycystic Ovarian Syndrome (PCOS)
Hormone disorder causing: Irregular cycle, excess levels of male hormone androgen, cysts on ovaries.
Adaptive thermogenesis
Metabolic adaptation in energy expenditure due to changes in energy intake (ie- lower BMR as a person loses weight, leading to less cals needed)
Nutrition Facts Panel
The usual summary
Added sugars less than what %?
10%
Protein grams per kg & amt per sitting
1.6- 2.2g
2.4g if in cal defecit
20- 40g per meal
Carbs grams per kg
4- 7g
Fat cals as % of diet
20- 35%
Cals per kg for rec athlete
25- 35 cal/kg
