What property of fat cells make it so hard to loose weight and keep it off?
Their size can vary 20 fold, depending on the size of the fat droplet
It takes 6 month before fat cells apoptose when on a diet
How does leptin signal in response to increased weight?
Increase energy expenditure
Why must you be wary when refeeding people after a long starvation?
The intestinal villi degenerate = reduced capacity to absorb nutrients = bacterial overgrowth = sepsis = death
What is the normal BMI range?
18.5-25
How much muscle mass can a person with 12kg of protein lose before it causes too much stress?
400g
What is aponectin?
It’s an anti-inflammatory peptide secreted by adipocytes to activate fatty-acid oxidation, glucose uptake and lactate production in muscle.
= It’s good, having low levels is bad
Which structure does leptin signal to?
The hypothalamus
What is cachexia?
Pathological muscle and fat loss due to overproduction of TNF-alpha - seen in cancer
What determines the weight set point in humans?
Leptin level
What is ghrelin do to hunger?
Stimulates it via NPY release of arcuate nucleus in hypothalamus
Why don’t most obese people respond to leptin?
They have low leptin receptor activity
What waist circumference is associated with increase risk of metabolic complications in women?
>80cm
What is the difference between Kwashiorkor and Marasmus?
Kwashiorkor is predominantly protein deficiency > there is oedema and some subcutaneous fat
Marasmus is generalised malnurishment > Skin and bones appearance
What waist circumference is associated with increased risk of metabolic complications in men?
>94cm
Why do people develop lactose intolerance?
Lactase production drops
