Over the years I've noticed that if I lose too much sleep, it triggers an almost insatiable hunger cycle. Normally I sleep well but the past four or five days, I haven't and yesterday the hunger cycle struck with a vengeance.
Those of you who have experienced this cycle know that it's not just "being hungry," it's like a sick, gnawing animal demanding food ... especially, for me, carbohydrates. Fortunately, I now recognize the symptoms and can handle it with relative sanity without going into a full-blown sugar overload, which just prolongs the cycle. And, I managed to sleep last night so this morning, the gnawing seems to be gone. But, it made me curious about the physiology of this strange cycle.
It turns out that the level of ghrelin, a 28 amino acid hunger-stimulating peptide and hormone, rises when we lose sleep. Not only does this hormone activate hunger, it stimulates the accumulation of fat, especially in the abdomen ... and makes sweet, high-calorie foods particularly attractive. When you're in a high-grelin state, carrots just don't cut it. Ghrelin levels decline just after eating so one way of coping with this hunger cycle is to eat just enough to "feed the beast" frequently.
Grehlin isn't all bad ... it enhances learning and memory and the ability to adapt to change ... which means that staying hungry when we're trying to learn something is a good strategy. One evolutionary theory is that grehlin was a way to keep us sharp ... and hungry ... while hunting for food. So, we're here because our ancestors were pumped full of ghrelin but now that chocolate is as close as the corner store, we have to learn to live with its effects.
While I recognize that yesterday's bout with grehlin was extreme and debilitating, there is an argument for managing the knife-edge of grehlin (hunger) in order to stay in a high-functioning mental state. J Stanton in her/his blog offers a poetic description of the "grehlin dance"
I am a ghrelin addict.
I dance on the knife edge of keen mental acuity and dopamine rush.
The hunger gnaws at my insides until I can feel my gut twisting itself into knots. Yet I gladly suffer the pain in order to wield ghrelin’s power. It is my cursed sword and its power is terrifying and intoxicating and it exacts its price from me, and I pay that price with an evil grin, because it is a power I could not wield any other way.
I am a ghrelin addict, and this is my story.
One sad note in my exploration of ghrelin is the obvious direction of the medical world to find a drug to "fix ghrelin." Obviously, obesity is a major concern in our world and finding ways to help people reach and maintain normal weight is extremely important. But, what side effects might come with a drug that moderates ghrelin ... might we create a world of skinny zombies?
Ever onward and back to packing!
"I am a ghrelin addict" ... http://www.gnolls.org/79/i-am-a-ghrelin-addict/