nutrition lect 1 cont Flashcards
what is the major source of carbohydrates that we consume ?
plants
Dietary fiber is defined :
non digestible carbohydrates and lignin (a complex polymer of phenyl propanoid subunits) present in plants.
*High fructose corn syrup (HFCS) is :
corn syrups that have undergone enzymatic
processing. to convert their glucose into
fructose
*Composition and metabolism of HFCS
and sucrose. differ that :
HFCS is ingested as a mixture of
monosaccharides.
Recommended intake(AI) for total fiber: :
38g/d for men
25g/d for women
Soluble fibers delay gastric emptying and also :
sensation of fullness
and
reduce peaks of blood glucose following a meal.
Soluble fibers lowers total and LDL cholesterol
levels by
increasing fecal bile acid excretion
and interfering with bile acid reabsorption
The main role of dietary protein:
maintenance of tissue
structure ,function and integrity.
Some amino acids are precursors of biologically active compounds, e.g.
epinephrine, serotonin.
*In case of dietary restriction, dietary protein is used as
energy after removal of amino group and
conversion into glucose or keto acids and fatty acids.
Positive nitrogen balance occur :
child development
pregnancy
recovery from illness (convalescing)
Negative nitrogen balance occur :
Dietary intake is insufficient
One of the essential amino acids is deficient
stress as in injury , sepsis, and cancer
protein loss e.g. nephrotic syndrome, burns
*Quality of proteins is measured by :
ability to provide the essential amino acids required for tissue maintenance.
*Protein Digestibility Corrected Amino Acid Score
(PDCAAS) is:
the standard adopted to evaluate
protein quality.
PDCAAS is based upon :
profile of essential AA and digestibility of protein.