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