nutrition Flashcards
important things about carbohydrates
most efficient energy source
classified as simple or complex
not all carbs are digested or absorbed at the same rate
Sugars mono vs disaccarides
monosaccharides or simple sugars (glucose) found mostly in fruits, syrups and honey
disaccharides are a combination of two monosaccarides (sucrose or lactose)
Starches
made up of long chains of glucose units (rice, potatoes, bread)
the body cannot use starches and many sugars directly from the food source
must be broken down during digestion and metabolism
where is glucose stored
as glycogen and in the liver and muscle cells
how much glycogen does the body store
a limited number (in liver and muscle cells) if extra, stored, it is converted to body fat
when inadequate glucose, what will the body use for energy?
protein
but the protein is then diverted from it own important function
important to have all essential food groups
what is glycolysis
process that breaks down glucose to produce energy
fiber - tell me some things about it
not digested by humans
not found in animal sources of food
forms the structural parts of plants
aids normal elimination by reducing the amount of time required for wastes to move through digestive tract
reduces risk of colon cancer and coronary artery disease
helps lower obesity, constipation, colitis, apppendicitis, diabetes
~ 25grams/day
soluble fiber
oatmeal, legumes, some fruit
bind to cholesterol and prevent its absorption which can reduce blood cholesterol levels
insoluble fiber
whole grain breads, bran cereals
lipids/fats
50% of canadians fat intake comes from two of the food groups
meat and alternatives and
milk and alternatives
functions of fats
supply energy define body shape insulation protect internal organs lubricates body surfaces vitamin carrier hunger depressor contribute to texture, taste, flavour and aroma to food
triglycerides (TA)
every triglycerides contains: one molecule of glycerol 3 fatty acids methyl group carboxylic acid group
sterols
part of compounds in the body
bile acids
sex hormones
found in plants and animal products
phospholipids
composed of glycerol 2 fatty acids phosphate group choline part of cell membrane found in eggs, liver, soybeans, wheat germ, peanuts act as emulsifier in mayonnaise, salad dressing, pudding
classification of fatty acids
number of carbon atoms
number of double bonds
position of first double bond
omega 6 fatty acid
linoleic acid essential for growth maintain integrity of skin and hair deficiency - dermatitis, skin lesions blood clotting
hydrogenation of fatty acids
changes a liquid to a solid
pros: protects against oxidation
alters the texture of foods
cons: makes PUFAs (polyunsaturated fatty acids) more saturated
changes the molecule from cis to trans fatty acid
linked to CVD
*can decrease the number of double bonds, some of the cis-double bonds are converte to trans double bonds
this results in high trans fat (which tends to be solid at room temperature
cholesterol is made where?
made in the body, from glucose and fatty acids in the liver
vitamin D is made from cholesterol in the body
used to make several hormones includes estrogen and testosterone
good cholesterol
HDL-C
bad cholesterol
LDL-C
plant sterol
found in corn, rye, wheat, seeds, nuts, legumes, vegetable oils - hydrogenated into margarine
consuming 1.3g/day of plant sterol can decreasetotal blood cholesterol and LDL-C
fat digestion system
mouth - lingual lipase
stomach - lingual and gastric lipase
small intestine - secretin, cholecystokinin, Bile (emulsifies fat), intestinal and pancreatic lipase
large intestine - fat trapped in fibre gets excreted
energy release from fat
adipocytes (fat cells) - site of fat storage - typically stored as triglycerides
mobilization- utilizing fatty acids is lipolysis
triglycerides are split into fatty acids and glycerol
LPL
lipoprotein lipase breaks down triglycerides from lipoprotein, producing glycerol and fatty acids
HSL
hormone sensitive lipase drives lipolysis (HSL found in adipocytes)
lipids are either stored in adipocytes or used for energy
metabolism of fats
beta-oxidation: breakdown of fatty acids to acetyl CoA
gluconeogenesis: the making of glucose from non CHO from TG and amino acids from proteins
how does the body adapt to insufficient glucose
by combining acetyl CoA fragments (derived from fatty acids to produce ketone bodies
ketone bodies are compounds produced during the incomplete breakdown of fat when glucose is no available
heatlth effects of fat
saturated fats in the diet raises blood cholesterol
hydrogenated foods contain trans fatty acids
trans- fatty acids in the diet increase LDL-C and decrease HDL-C
obesity can be a consequence of high-fat, high-kcalorie diets in excess of energy needs
replacing saturated and trans fats with MUFA and PUFA is most effective dietary strategy in preventing heart disease
functions of protein
provide structure: growth movement: contraction transportation: lipoproteins enzymes: digestion hormones: insulin antibodies: protection from infection fluid and electrolyte balance acid-base balance maintain pH energy : 4kcal/gram
all amino acids are composed of:
carbon, hydrogen, oxygen, nitrogen (some sulphur)
all amino acids have the same basic structure:
a central carbon (C) an acid group (COOH) a hydrogen (H) an amino group (NH2) R group ( makes one amino different from another)
9 essential amino acids
histidine threonine valine tryptophan isoleucine leucine lysine phenylalanine methionine
**cannot be make in the body- must be supplied by diet*
11 non-essential amino acids
alanine arginine asparagine aspartic acid cysteine glutamic acid glutamine lysine proline seine tyrosine
the liver makes the non essential amino acids
deamination
removal of the NH2 group
transmination
transfer of nitrogen
once the NH2 group is removed from the amino acid, nitrogen is transferred between amino acid and keto acids to produce non-essential amino acids
peptide bond
a bond that connects amino acids together
dipeptide: 2
trypeptide: 3
polypeptide: 4
oligopeptide: 4-9
digestion/absorption of protein
enzyme hydrolyzes a protein = protease
protein digestion begins in stomach
(CHO/fat digestion begins in mouth)
gastrin triggers the release of HCl
2 main functions of HCl
denatures protein (takes it apart) activates pepsinogen (gastric juice) into its active form called pepsin (breaks peptide bonds (shorter chain polypeptides and some free amino acids)
small intestine protein digestion
smaller polypeptides and amino acids to and release secretin: signals the pancreas to release bicarbonate into the SI to neutralize the stomach acid and to inactivate pepsin
cholycystokin: activated enzymes to further breakdown protein (trypsinogen to trypsin)
recommended protein requirements for top elite endurance athletes
1.6g/kg
top elite strength athlete: 1.76g/kg
kwashiorkor
pure protein deficiency
marasmus
energy and protein deficiency
*not typically seen in North America
elevated protein intakes over long periods of time can result in:
dehydration kidney function issues bone health issues kidney stones increase risk of heart disease and cancer
ovalbumin
main protein in eggs
casein
main protein in milk
water soluble vitamins
vitamin C: ascorbic acid
B1 vitamin (name and function)
thiamin
main function: part of coenzyme group require to get energy from CHO, Protein and Fats
water soluble
destroyed by heat
Thiamine pyrophosphate (coenzyme group)
- absence of this form will produce symptoms of beri beri
- TPP is part of nerve cells - needed for nerve function
B vitamins functions
part of coenzymes to help get energy from CHO, fats and protein
some are necessary for RBC formation and are called hematopoietic vitamins (vitamin B12 and folate)
Thiamine pyrophosphate is needed for two major functions:
pyruvate: acetyl CoA + CO2
a-ketoglutarate: succinyl CoA + CO2 (Krebs Cycle)
Clinical deficiencies of thiamin
infantile: infants
wet: severe edema
dry: muscle wasting, legs cramps
cerebral: wernicke-korsakoff syndrome
- severe thiamine deficiency due to excess alcohol consumption as it interferes with thiamine
- symptoms: staggering gait, disorientation, loss of short term memory and jerky eye movements
B2 (name and function)
Riboflavin
main function: part of two coenzyme groups
1. FMN: flavin mononucleotide
2. FAD: flavin adenine dinucleotide
soluble in water
destroyed in light - opaque milk containers are used to prevent decomposition of riboflavin in milk
deficiency in riboflavin
ariboflavinosis
symptoms: cheilosis - cracks in skin and corner of mouth
glossitis: swollen tongue due to atrophy of tissue
ocular disorders: formation of extra blood cells in the eyes, itchy eyes, sensitive to light
B3 (name and function)
Niacin
main function: coenzyme to get energy from CHO, protein and fats
1. NAD: nicotinamide adenine dinucleotide
2. NADP: nicotinamide adenine dinucleotide phosphate
soluble in water
tryptophan is precursor and this conversion requires: thiamin, riboflavin and B6
deficiency of niacin
Pellagra
dermatitis: effect on skin (rash, dry, flakes, darkens)
diarrhea: intestines become inflammed
dementia: mental behaviour, mental confusion
death: if not cured
B7
Biotin:
water soluble
contain sulphur
avidin (raw egg whites) inteferes with biotin absorption
combines with biotin and prevents it from being absorbed
found in most foods
B5 (name and function)
pantothenic acid
supplements sold to help boost energy
B6 (name and function)
complex of 3 closely related compounds: pyridoxine (alcohol), pyridoxal (aldehyde) and pyridoxamine (amino group)
main function: part of coenzyme group to get energy from fats and proteins
required to convert tryptophan to niacin
involved in central nervous function
taking more than 2grams/day can cause toxic concentration in the body
after absorption, all 3 converted to it coenzyme form called pyridoxal phosphate PLP
deficiency in B6
depression, confusion, enemia
involved in many biomechanical reactions in the body
Folate
folic acid
main function: part of coenzyme to help make DNA for new cell growth
deficiency in folic acid
red blood cells dont divide - anemia
required for brain development
high levels of folate MAY help alzheimers patients to improve memory
sources: spinach, avocado, broccoli, skim milk, beans, lentils, oat bran bagel
B12
Cobalamin:
part of coenzymes to make DNA for new cell growth
deficiency in B12
pernicious anemia
minerals
critical for bone health, nerve conduction, hematological health, intracellular processes
major minerals
sodium (Na) Potassium (K) Chloride (Cl) Phosphorous (P) Magnesium (Mg) Sulphur (S) Calcium (Ca)
Minor minerals
copper selenium Manganese iodine fluoride cobalt chromium vanadium boron zinc molybdenum iron
Sodium (& everything u can tell me about it)
DRI: 1200-1500 mg/day
functions: fluid and electrolyte balance, neural signaling, muscle contraction
toxicity: edema, acute hypertension (renal disease, diabetes, obesity)
Chloride (& everything u can tell me about it)
DRI: 1800-2100mg/day
functions: fluid and electrolyte balance, component of HCl
deficiency: unlikely unless prolonged sweating, diarrhea, vomiting
toxicity: vomiting
Potassium (& everything u can tell me about it)
DRI: 4700mg/day
functions: fluid and electrolyte balance, neuronal signaling, muscle contraction
deficiency: mm weakness, paralysis, confusion, decreased potassium= high blood pressure
toxicity: mm weakness, vomiting
magnesium (& everything u can tell me about it)
DRI: men 400mg/day vs women 310mg/day
function: cofactor in any reaction involving ATP, component to bone electrolyte, inhibits phosphorus absorption
deficiency: alter any energy requirement process, inhibition of parathyroid hormone release, hypertension
toxicity: vomiting, diarrhea, dehydration, double vision, slurred speech
phosphorus (& everything u can tell me about it)
DRI: 700mg/day
functions: mineralization of bones and teeth, phospholipids (ATP), acid buffer, ViT D stimulates absorption
deficiency: rare though drug interaction, Mg, Ca, Al, impair absoption, crohns disease, alcoholism, weakness and bone pain
toxicity: bone calcification
calcium (& everything u can tell me about it)
DRI: 1000-1200mg/day
functions: mineralization of bones and teeth, muscle contraction, blood clotting, BP control
deficiency: decreased growth in children, osteoporosis
toxicity: constipation, kidney stone formation, kidney dysfunction, interference with absorption of other minerals
Zinc (& everything u can tell me about it)
DRI: 8011mg/day
functions: cofactor in trancription regulation, cofactor in many enzyme reactions, insulin, sperm production, immune function, taste perception
deficiency: low insulin, growth restriction in fetus, poor taste, weight loss, diarrhea, nausea, night blindness, reproduction dysfunction
toxicity: fever, nausea, vomiting, diarrhea
Iodine (& everything u can tell me about it)
DRI: 150ug/day
function: component of thyroid hormones (regulation of growth, metabolism, development)
deficiency: enlargement of thyroid gland, weight gain, mental and physical problems in infants
toxicity: thyroid enlargement
Copper (& everything u can tell me about it)
DRI: 900ug/day
function: cofactor in reactions, collagen formation, electron transport chain, oxidation of iron
deficiency: uptake inhibited by vit C, fiber and zinc, free radical damage, poor iron transport
toxicity: liver disease, decrease uptake of zinc
Fluoride (& everything u can tell me about it)
DRI: 1.8-4mg/day
function: makes bones stronger, tooth decay resistance
deficiency: increased suseptibility to tooth decay
toxicity: tooth discolouration, increase bone density, nausea, vomiting, chest pain
iron (& everything u can tell me about it)
DRI: men 8mg/day women 18mg/day
function: hemoglobin (80% of bodys iron), myoglobin (muscle) and metabolic reactions
deficiency: weakness, tiredness, reduced learning ability, itching, pale nail beds, impaired wound healing, iron deficiency anemia
toxicity: infections (vit C in high does release ferritin), lethargy, pigmentation, loss of hair, impotence, death
anemia
decrease in hemoglobin after prolonged iron deficiency, decreased RBC ability to carry oxygen, compounded by blood loss, blood donation, illness, pregnancy
heme
comes from animals and accounts for about 10% of the average iron intake well absorbed (25%)
nonheme
comes from plants and animals and accounts for 90% of the remaining iron, but it not well absorbed (17%)
iron and athletes (most important notes)
iron is lost through sweat
supplements needed for altitude training
calcium and athletes (most important notes)
significant loss during sweating
increase intake prevents bone loss
prevention of stress fractures
phosphorus and athletes (most important notes)
can impact calcium ratio
(supplements) can cause GI distress
might enhance oxygen release at the muscle
act as acid buffer during high intensity exercises
sodium, potassium, chloride and athletes (most important notes)
hypoatremia with prolonged sweating and no electrolyte replacement
loss with sweat
deficiencies can impair heart, muscle and neuron firing
cramping
decrease cardiovascular performance
magnesium and athletes (most important notes)
loss during sweat
supplements did not increase aerobic or anaerobic performance
zinc and athletes (most important notes)
exercise can deplete zinc in some athletes
low levels lead to poor aerobic performance and strength
copper and athletes (most important notes)
chronic strenuous exercise may deplete levels
no improvement through supplements
iodine and athletes (most important notes)
correlation between iodine loss and exercise
low level intakes in figure skaters and weightlifters
female athlete triad (those at risk)
sports with subjective scoring
endurance sports
sports with weight categories
female athlete triad (warning signs)
excessive dieting for weight loss irregular or absent menstrual cycle stress fractures self-esteem and mood depicted by body image compulsive overexercising
amenorrhea
combination of high exercise intensity and inadequate caloric intake
amenorrheic
> 3 months without menstruation
oligomenorrehic
2-3 months between menstrual periods
eumenorrheic
normal monthly menstrual periods
female athlete triad cycle
menstrual dysfunction (delayed menarche, absence of cycle) disordered eating (anorexia, bulimia) osteoporosis (increase risk fo stress #, low bone density)
Creatine (most important notes)
red meat
can deplete in 10-12 seconds
acute response: no improvement of aerobic performance
high intensity, short duration, repeated bout exercise improved
chronic long term: increase in fat free mass, increase in maximal force and power output, increase in high intensity, short duration, repeated bout
side effects: weight gain, GI distress
caffeine(most important notes)
stimulant actions, lipolysis, glycogenolysis, alters substrate use
stimulates CNS (alertness, mood)
regulates CA and glycogen breakdown
FFA mobilization
performance: 200-400mg
increases performance in SOME endurance events, individual variation, NO effect on high power output activities
Ginseng (most important notes)
stimulant, energy, antioxidant, immunomodulator, adaptogen
controversial effects on endurance performance
may effect mood and arousal
glucosamine (most important notes)
necessary for cartilage growth, repair and lubrication
1500-2000mg will reduce some symptoms of early stage osteoarthritis
glutamine (most important notes)
improved immune function, muscle mass, energy
Androstenedione (Andro) and dehydroepiandrosterone (DHEA) (most important notes)
preprohormones in pathway of testosterone and estrogen synthesis
synthesizes in the body from cholesterol
increase mm mass, strength
bicarbonate (HCO3-)
water is by product
improvement of high intensity endurance activities
green tea extract (most important notes)
protection from disease, antioxidant
- evidence for a variety of disease prevention effects
improved metabolic handling of fats and glucose
epidemiological indirect
Vitamin C
ascorbic acid
function: is a nutrient your body needs to form blood vessels, cartilage, muscle and collagen in bones. Vitamin C is also vital to your body’s healing process.
Vitamin C is an antioxidant that helps protect your cells against the effects of free radicals — molecules produced when your body breaks down food or is exposed to tobacco smoke and radiation from the sun, X-rays or other sources. Free radicals might play a role in heart disease, cancer and other diseases. Vitamin C also helps your body absorb and store iron.
Most people get enough vitamin C from a healthy diet. Vitamin C deficiency is more likely in people who:
Smoke or are exposed to secondhand smoking
Have certain gastrointestinal conditions or certain types of cancer
Have a limited diet that doesn’t regularly include fruits and vegetables
Severe vitamin C deficiency can lead to a disease called scurvy, which causes anemia, bleeding gums, bruising and poor wound healing.
Vitamin D
Calcidol:
necessary for building and maintaining healthy bones. That’s because calcium, the primary component of bone, can only be absorbed by your body when vitamin D is present. Your body makes vitamin D when direct sunlight converts a chemical in your skin into an active form of the vitamin (calciferol).
Vitamin D isn’t found in many foods, but you can get it from fortified milk, fortified cereal, and fatty fish such as salmon, mackerel and sardines.
The amount of vitamin D your skin makes depends on many factors, including the time of day, season, latitude and your skin pigmentation. Depending on where you live and your lifestyle, vitamin D production might decrease or be completely absent during the winter months. Sunscreen, while important, also can decrease vitamin D production.
Many older adults don’t get regular exposure to sunlight and have trouble absorbing vitamin D, so taking a multivitamin with vitamin D will likely help improve bone health. The recommended daily amount of vitamin D is 400 international units (IU) for children up to age 12 months, 600 IU for ages 1 to 70 years, and 800 IU for people over 70 years.
