Gut Hormones 101: What Role Does Ghrelin Play in my Body?

It’s 12:00pm, and your lunch break is in half an hour. Your stomach is starting to sound more like a pack of communicating whales, and your co-workers in the cubicles next to you are becoming concerned. You can’t concentrate, and all you are thinking about is your delicious lunch. So why are you so hungry, even though you have had a snack an hour ago?

It’s all thanks to a hormone called ghrelin.

Ghrelin is known as the “fast-acting hunger hormone.” Its main function is to increase appetite so that you seek out (and eat) food.

Ghrelin is secreted mainly from the stomach into the bloodstream. From the bloodstream, ghrelin travels to the brain where it acts on the hypothalamus. The hypothalamus is the part of the brain that governs hormones and appetite. The more ghrelin that is secreted by your gut, the hungrier you will feel. In turn, the more food that is consumed, and the lower the ghrelin levels will fall. In addition to increasing feelings of hunger, ghrelin also plays a role in stimulating gut mobility and stomach acid secretion, preparing your body for the digestion of food.

After bariatric surgeries, ghrelin levels decrease. For many people, having less hunger cues is helpful in managing a healthier body weight.

So next time hunger strikes, blame it on the hunger hormone, ghrelin!

Blog post contributed by Alyssa Ramuscak, Nutrition & Dietetics Student, University of Western Ontario