Flashcards in Nutrition Deck (45):
what are the 2 functions of nutrients?
provide energy - macronutrients
what make up the macromolecules?
what make up the essential molecules/micronutrients?
essential fatty acids
what 3 factors make up the dailt energy expendature (DEE)?
3.energy required to process food (thermogenesis)
what factors affect RMR/BMR?
what is Diet-induced Thermogenesis (DIT)?
the energy required to digest, absorb, distribute and store nutrients - about 10% of RMR/day
what are the percentages of caloric intake from macronutrients?
carbs - 50% - most important
Fat - 30%
protein - 20%
what is the energy contribution of carbohydrates, protein, fat and alcohol (kcal/g)?
what are the 3 categories of carnohydrates?
what are sources of monosaccharides?
- fruits, sweet corn, corn syrup, honey
what are sources of dissaccharides?
sucrose - table sugar
lactose -milk sugar
maltose - in beer and malt liquors
what makes up sucrose?
glucose and fructose
what makes up lactose?
glucose and galactose
what makes up maltose?
glucose and glucose
what are sources of polysaccharides?
complex carbs - polymers of glucose
do NOT have a sweet taste
Starches - found in plants
-wheat, grains, potatoes, dried peas, beans, vegetables.
how are polysaccharides classified?
base on how they affect blood glucose levels
what is glycemic index?
time course of rise and decline of blood glucose after a meal
what does fiber contain?
includes cellulose, lignin, pectin
Does not provide energy
what could too much fiber do?
decrease absorption of fat-soluble vitamins and bind to trace elements like zinc
what are the most important class of dietary fat from an energy perspective?
what percentage of total dietary lipid does TAGs contribute?
which plant sources do not have a source of unsaturated FA (good kind) and more saturated (bad)?
pal oil exceptions
maybe good for skin
what provides the essential FA?
linoleic and alpha linolenic acids
when does arachidonic acid become essential?
if or when linoleic acid is insufficient/deficient
what are EFA required for?
membrane fluidity and synthesis of eicosanoids
what are deficiency of EFAs characterized by (not common)?
poor wound healing
whats the general dietary goal when it comes to fats?
decrease saturated fat (TAGs)
increase mono or poly unsaturated FA
what cannot be stored?
what is the function of proteins?
replenish body proteins
required for essential aa
what proteins have a high biological value?
proteins from animal sources
what does high biological value mean?
contain high amounts of essential aa required for synthesis of human tissue
what has a low biological value?
when is nitrogen intake greater than nitrogen excretion [positive nitrogen balance]?
when tissue growth is occurring - growing kids, pregnancy, during recovery from surgery/trauma
what balanceare healthy individuals in?
when is nitrogen excretion greater than nitrogen intake [negative nitrogen balance]?
inadequate deitary protein
lack of essential aa
physiology stress - trauma, burns, illness, surgery
what are some diseases greatly influenced by?
what is the major contributor of serum cholesterol?
LDL - from TAGs and VLDL
what kind of effect does reducing dietary cholesterol have on serum cholesterol?
how can you reduce serum cholesterol?
1. reduce saturated FA (TAGs), increase mono and poly unsaturated FA
2. decrease de novo synthesis of cholesterol by statins or something else
what are the long term signals of hormonal regulation of weight and energy?
where is leptin produced? what is it?
produced proportionally to fat cell density and plays a key role in weight gain, appetite suppression and energy expenditure through its actions on the HYPOTHALAMUS!
it also regulated inflammatory responses, blood pressure and bone density
what does insulin do?
similar to leptin
dampens appetite by exerting its effects on the HYPOTHALAMUS
what are the short term signals of hormonal regulation of appetite?
what is Ghrelin?
secreted by endocrine cells of stomach
increase the release of NPY - which enhances appetite and food intake
ghrelin release is activated by fasting and low glucose
inhibited by high glucose