undernutrition Flashcards
what are aetiological factors of nutritional diseases?
when disease caused by nutrition (deficiency or excess)
what are generalised and specific udernutrition?
generalised - deficiency of calories
specific - deficiency of an essential nutrient
what are primary and secondary undernutrition?
primary - related to the diet
secondary - related to an illness or a condition
what is PEM as a consequence of undernutrition?
Protein-Energy Malnutrition
affects every organ and system in body
what does form of PEM depend on and what are the 2 forms?
depends on protein-carb balance
dry = marasmus (general) - severe calorie and protein deficiency and oedema doesn’t occur
wet = kwashiorkor (specific) - proetin deficiency with adequate calories from carbs and oedema occurs
how does low protein lead to oedema?
low protein reduces synthesis of blood proteins, esp. albumin
low protein in blood has osmotic effect and causes water to diffuse into interstitial fluid (oedema)
what is the energy balance equation?
energy intake = energy expenditure +- energy stored
what do the laws of thermodynamics dictate?
and what do they not tell us?
that a negative energy balance will result in reduced energy stores
don’t tell us how
how is adipose tisue fatty acid flow affected by positive and negative energy balances?
and what is meant by positive and negative fatty acid flow?
means whether fat towards to be stored or away to be used
positive
- go from negative (fatty acid flow away from tissue) in morning
- to positive after breakfast (fatty acid flow towards tissue to be stored)
- then reduces as effects of meal wear off etc/
negative
- negative fatty acid flow overnight
- small breakfast won’t lead to any fat storage and instead used (negative)
- net negative flow of fatty acid away from adipose tissue
role of protein in negative fatty acid flow?
protein can maintain muscle mass and inhibit flow
what are the 3 causes of undernutrition?
- reduced delivery of nutrients to the gastrointestinal system
- increased demand for nutrients
- inability for gastrointestinal system to absorb nutrients
discuss reasons for reduced delivery of nutrients to the gastrointestinal system as a cause for undernutrition?
decreased food availability
mechanical - problem with getting food into digestive system e.g impaired oesophagus
functional/neurological - e.g anorexia
dicuss reasons for increased demand for nutrients as a cause for undernutirion?
physiological - e.g exercise or pregnancy
pathophysiological - disease increasing metabolic rate e.g cancer
discuss reasons for inability for gastrointestinal system to absorb nutrients as a cause for undernutrition?
intrinsic problem - e.g celiac disease
post-surgery - e.g bariatric surgery
describe cancer cachexia as a cause for undernutrition?
tumour requires energy as uses energy
releases substances e.g cytokines (inhibit NPY which promotes appetite) to get body to release this energy
so reduce muscle tissue and mass due to increased metabolism not matched with an increased energy intake
