Week 5 readings summary Flashcards
define obesity
excess body fat accumulation with multiple organ specific pathological consequences
methods for assessing obesity
BMI (most common)
Waist circumference
aetiology of obesity
The result of chronic imbalance between energy intake and energy expenditure - energy intake exceeds energy expenditure over prolonger period
Some factors that determine energy intake and energy expenditure appear to be outside of conscious control
what are the 3 components of 24 hour EE?
RMR
thermic effect of feeding
EE due to PA
what influences food intake and EE? may also be responsible for the imbalance
hormones
examples of hormones
leptin
ghrelin
oxyntomodulin
PPY
what is ghrelin?
Only hormone that stimulates appetite, all other are satiety signals. Ghrelin conc rises prior to meals, suggesting it plays role on initiating food intake. Very low in those who have has gastric bypass - contributing to their further weight loss.
what is oxyntomodulin?
reduces energy intake and increases 24 hr EE, can be anti-obesity therapy
what is PPY?
levels rise sharply after meals, reducing food intake, defective PPY secretion may play a role in obesity
genes affecting obesity
Defective OB gene responsible for leptin production
Defective MC4R - leads to overeating
what is the VITAI study? (vitamins and lifestyle study)
Found high levels of PA associated with lower weight gain over time
Other studies have found that although PA attenuates the weight gain associated with ageing, it does not prevent it completely
what is NEAT?
non exercise activity thermogenesis
NEAT may be biologically determined and the obesity epidemic may reflect the emergence of a chair-enticing env. To which those with an innate tendency to sit, do so, and become obese
3 drugs for weight maintenance
Orlistat
Sibureamine
Rimbonant
*most effective when combined with PA
