principles of nutrition Flashcards
nutrition
sum of processes for living organism to receive and use materials from environment to promote its own vital activities
essential nutrient
substance necessary for life
cannot be synthesised by the body
food
substance eaten digested and absorbed
diet
food selected
balanced = adequate amount of nutrients
malnutritio
incorrect amount of one or more nutrients in diet
nutritional status
balance between intake of nutrients and requirement at that period in time
nutritional assessment
measurement of nutritional stasis
metabolism
changes constantly taking place in body due to tissue activity, transformation
catabolism
complex molecules to simple
releases energy
anabolism
simple to complex molecules
requires energy
nutrients and roles
1) carbohydrates
- heat and energy
2) fats
- heat and energy
- incorporated into body tissue
3) proteins
- tissue formation and repair
- broken down to produce energy
4) vitamins and minerals
- for regulation of body processes
- incorporated into tissue (minerals)
5) water
- fluid medium essential for metabolism
- temperature regulated
- waste product excretion
measurement of nutrients in food
calorie
measured by oxidation of food
carbs consitst of
hydrogen and oxygen and C
types of carbs
monsaccharides (glucose, fructose, galactose))
disaccharides (pairs surcrose, lactose, Maltose)
polysaccharides e.g. starch
non starch polysaccharides advantages
- bulky and take longer to eat
- prolonged and feeling of fullness as stay in stomach longer
- prevent constipation, colonic cancer
(NSP and carcinogens: bind, dilutes by increasing faecal bulk, decrease transit time, therefore reduced exposure)
non starch polysaccharides dis
- bind to minerals (Ca Fe) grt deficiencies
- wind from metabolism of NSP in caecum/colon: methane, CO2, H2 (dependant on type of NSP and bacterial flora)
- insufficient energy intake (bulky, take longer to eat)
carb digestion
broken by enzymes to monosaccharides Liver can then 1) converted into glycogen - stored in muscles and liver 2) convert into fat - when glycogen stores are full 3) metabolised for energy - eg glucose only for brain, NS, RBCs
glycemic index
ranks carbs at the rate where carbs reach bloodstream as glucose
low GI
slow release
constant and stable
help reduce insulin resistance and weight control
glycaemic reponsce may be different for indiivduals
what happens if too much fat is metabolised too quickly
ketoacidosis
could cause protein breakdown to release energy
- caused by intake of carbs reduced
free sugar
added sugar plus those naturally present in honey ect
fats consist of
carbon
hydrogen
oxygen
types of fats
saturated
monounsaturated
polyunsaturated
combine with glycerol to form triglycerides
trans fatty acids
hydrogenated
man made
essentil fatty acids
structure and function of cell membranes
to regulate cholesterol metabolisms
cholesterol
LDL/HDL
from diet and also synthesised in the body
oils
fats that are liquid below 20 degrees
functions of fats
1) energy for tissue activity and body temperature maintenance
2) incorporated into body structure
3) hold position and protection of vital organs (visceral)
4) insulation (subcutaneous heat loss)
5) satiety (presence in duodenum delays stomach emptying
6) provide fat soluble vitamins and assist absorption
where are fat body stores
under skin
around abdominal organs
dietary intake fats
35%
protiens
chains of aa
CO2 and H20 and nitrogen containing compounds grt aa
protein functions
replacement during metabolism and weat
new tissue production
forming enzyme
energy source
digestion and fat of protein
into aa dipeptides an tripeptides Fate - structural pprotiens - converted to other aa oxidised for energy
Vit C
essential for normal metaolbims
lack of leads to scurvy
vit D
diet plus made in body converted in skin by UV
how is Fit K made
intestinal bacterai
types of vitamin
water solube
C and B
fat soluble
- A D E K
minerals
form part of body constituents soft tissue ec
haemolgoin
iron containing oxygen transport metallo protien
water is needed fro
secretions excretions
sufficient urine flow
joint lubricati
temp cotrol
water is lost
- via urine
- faces
- sweat
- exhaling
- vomiting
- diarrhoea
- haemorrhage
- exudate from burs
too much water
Kidneys cannot keep up with excretion
- blood dilutes
- lower salt concentration
- water moves from blood to cells and organs
- brain swells and prevents vital functions
energy needed for
- growth and maintenance of body tissues
- maintenance of body temperature
- voluntary and involuntary muscle movement (heat, GIT, respiration)
basal metabolism
- amount of energy required for basic life processes eg heartbeat, respiration, cellular activity
