[Steve Shafley]

Another comment by Lyle regarding insulin levels and blood pressure I found interesting:

wrt: high blood pressure, one function of insulin is to incresae sympathetic tone (a big part of the thermic effect of eating is due to this) so chronically high insulin = increased sympathetic tone

among other things, this tends to increase blood pressure

the insulin resistance of obesity is likely related to a bunch of different stuff

one of them is that when muscle gets packed full of nutrients (carbs, triglyeride or even aminos), it tends to become insulin resistant

when fat cells get full, they start releasing a host of chemicals (leptin, TNf-alpha, resistin which doesn't seem to do much in humans, adiponectin goes down, probably lots of other stuff) to
a. limit further calorie storage in fat cells
b. try to increase fat oxidation elsewhere (i.e. leptin drives fat oxidation in muscle).

also, since fat cells are not longer accepting nutrients, you get high blood fatty acid levels in the bloodstream, which also causes insulin resistance

a lack of activity plays a role

genetics plays a role