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33 Cards in this Set
- Front
- Back
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name the macronutrients
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fat
protein CHO |
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name the micronutrients
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minerals
fibre water vitamins |
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what is the equation for nutrient balance
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intake - output = change in body stores
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what type of malnutrition are there?
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overnutrition
under: micro or macro |
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what 3 questions should you ask about nutritional status?
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what are you
what do you eat what can i do? |
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what is the recommendation for dietary fibre
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18 - 25 grams
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where is it found?
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veg - plant cell walls, NSP
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soluble fibres are...
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pectin and glucan
soluble in water make stools soft and bulky good source of fermentation prevent constipation increase absorption of cholesterol by binding to bilases |
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insoluble fibres :
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in cellulose, whole grains, cereals
not absorbed substrate for fermentation attract water increase weight and bulk bind carcinogens |
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main role of dietary fibre
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speed up transit and bulking
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what does fermentation do?
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produces short chain fatty acids
provide energy butyrate; energy for colonocytes acetate: energy for liver also proprionate |
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what is a mineral?
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an inorganic element with a physiological function, they are essential and must be supplied by the diet
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what is calcium needed for?
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bones
cell signalling muscle function |
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sources of calcium;
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mik, dairy products,
added to flour in hard water |
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how does intestinal absorption of calcium work
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calbindin: calcium binding protein.
regulated by vitamin D - increases absorption |
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can calcium absorption be affected by foods?
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yes!
increased calcium intake decreases calcium absorption meal ingestion decreases calcium absorption phytates (phosphate salts, found in cereals/grains) can reduce absorption disease reduces absorption |
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what happens if there is low calcium?
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vitamin D produced released and parathyroid hormone released form parathyroid gland. together they
1) increase intestinal absorption 2) regulate release from bone 3) increase kidney reabsoption |
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describe the speed of calcium gain and when it happens
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decreases from birth but then increases in puberty
in adults: calcium loss and demineralisation from bone |
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what is peak bone mass
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the peak mass of bone in life, occurs at 30. after this you start demineralisation
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what affects peak bone mass?
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genetics
endocrine - GH, sex H, calcium Hormones smoking- reduces peak bone mass nutrients mechanical eg weight bearing exercise |
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is calcium plasma levels a good index of calcium stores?
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no! because calcium is so tightly regulated
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how does smoking effect calcium stores
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decreases parathyroid hormone, so can't save body from low calcium - results in demineralisation as it is released from bone
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what is iron needed for
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Hb
electron transport steroid synthesis; found in cytochrome P450 |
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where does the body store iron
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in the reticuloendothelial system
bone marrow liver spleen |
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is plasma ferritin a good indicator of iron stores?
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yes!
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what is transferrin
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protein that transfers ferrous iron to ferritin stores
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what is apoferritin
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ferritin without the iron
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where do we get haem iron from?
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meat
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do dietary factors have an affect on iron absorption?
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not really! except for a few things, like calcium decreases absorption
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why type of iron is more affected by dietary factors?
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non haem
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is ferrous or ferric iron absorped?
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ferrous 2+ so reducing agents increase absorption
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enhancers of iron absoption
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Organic aids – citric aid
Fructose, sorbitol Alcohol Some amino acids Meat Fe deficiency and anaemia Fasting Pregnancy Vitamin C |
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inhibitors of iron absorption
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- Tannins
- Polyphenols - Phosphates, phytates, - Bran, lignin - Proteins (soy protein) - Other minerals (Ca) - Fe overload - Achlorhydria - Cu deficiency |
