Dietary macronutrients and their roles Flashcards
Macronutrients
needed in gram quantities
Micronutrients
needed in milligrams or micrograms
Essential nutrients
cannot be made in the body
essential for growth and normal function
water/ inorganic nutrients/organic nutrients
Conditonally essential
not required in the diet but must be supplied to those who do not synthesize them.
Tyrosine/arginine/histidine/immature infants
nutrient requirements
essential a.a- Phe/val/tryp/threo/isole/meth/hist/arg/leu
essential f.a- linoleic acid/linolenic/ arachidonic
vit
minerals
carbohydrate requirement
55-65%
rice,wheat,maize,barley,oats
Available carbs
can be metabolized in the body
Complex carbs
not digested and absorbed easily
starch in millet grains, seeds and unripe bananas
Monosaccharides
glu/ galac/ fruc
corn syrup and high fructose corn syrup
Disaccharides
lactose in milk
maltose from starch and sprouts
trehalose- in yeast and mushrooms
sugar alcohols such as sorbitol
Maltodextrins
oligomers and polymer mixture
starch derived (alpha 1-4) and (alpha 1-6)
formed from partial hydrolysis of corn starch or wheat starch.
used as fat substitues
can be absorbed and digested like starch
non-alpha glucans
no alpha 1-4 and 1-6 contain galactose and fructose raffinose/stachyose/verbascose/inulin found in peas , beans and lentils non-digestible work as pre biotics
Prebiotics
fibre that function as food for the bacteria
feed on the bacteria in the gut.
Probiotics
microorganism that provide health benefits.
Polysaccharides (starch)
alpha glucans/ (15-30%) amylose and (70-85%)amylopectin.
three forms- A- cereal
B-potato and banana
C-legumes
Raw B- form starch that cant be digested in the intestine (resistant starch)
Modified starch
modified by substitution and crosslinking to reduce its degradation and change other properties
Non starch polysaccharides
dietary fibre components
Cellulose- beta glucans
Hemicellulose- xylose and arabinose
Pectins- galacturonic acid
Benefits of dietary fibres
increase bulk of feces
improve bowel movements
regulating blood cholestrol levels
increase intake reduce rates of colon cancer.
prebiotics and microbial flora
non-viable
benefit on the host associated with modulation of the microbiota
alter the balance of bacterial flora so there are more lactobacilli and bifidobacteria
what they do?lactobacilli and bifidobacteria?
maintain gut barriers to infection
synthesize b vitamins
breakdown carbohydrate and release metabolites to produce energy.
good prebiotics
Fructo-oligosaccharides, inulin, galacto-oligosaccharies
Glycemic index
extent to which a carbohydrate increases blood glucose level compared to a reference carb
depends on rate and extent of digestion, absorption and clearance from plasma.
Glycemic carb
provide glucose for metabolism after digestion and absorption in the small intestine.
Maltodextrins
non-glycemic carb
pass into large intestine undigested and are acted upon by bacteria
various oligo saccharides, NSP, and resistant starches
low glycemic index
whole grain containing are rich in dietary fibres.
reduce risk for type2 diabetes
improved glycemic control in both type1 and type2
minimum amount of carb intake to avoid ketosis
50g/day
min amount of free sugars
less than 10%
grams of NSP to be provided by whole grains, cereals and fruits.
25g
energy value per gram of carbohydrate
4 cal (17Kj)
