Ghrelin is a hormone produced in our gut. Ghrelin acts on our brain to promote hunger, but it also may play a key role in the pleasure associated with eating. Ghrelin makes us crave all of the processed foods on full display at twenty-four-hour convenience stores. Clinical investigator Shahrad Taheri’s 2004 study showed that as sleep duration goes down, ghrelin production goes up, increasing the likelihood of overeating and obesity.
