Mark’s Daily Apple has an interesting blog post on leptin. Here’s the intro, but click through for the good stuff.
Just about every physiological process occurring under the hood can be attributed to one hormone or another. Hormones are like software programs, directing our bodily processes, modulating our reactions to foods, and guiding energy metabolism and balance. We don’t consciously control our hormonal responses – that is, we don’t think to ourselves, “Hmm, let’s get some testosterone flowing,” or “Insulin: release!” But we can heavily influence our hormonal responses through the things we do, the stress we undergo, the foods we eat, the weights we lift, and the sleep we get.
Perhaps all those times someone said they were fat due to a hormonal or glandular problem, they were right!