Ghrelin and leptin are the two main hormones involved in regulating your appetite (1). Ghrelin is made in your stomach, and is responsible for sending signals to your brain to tell you when you’re hungry and it’s time to eat. Leptin is made by your fat cells, and is responsible for sending signals to your brain that you’re full (1).

As a shiftworker, you often have to be awake and active at non-traditional times (e.g., during the night), and then sleeping at non-traditional times (e.g., during the day). You may be eating at odd times as well. This can contribute to circadian disruption (read more about circadian disruption here). This disruption in your circadian rhythms can cause problems with the production and secretion of hormones, including ghrelin and leptin. In fact, for shiftworkers, we know that circadian disruption can cause higher levels of ghrelin and lower levels of leptin – this means higher hunger signals and lower fullness signals, which may lead you to eat more food more frequently than you otherwise would. This is one of the factors that can lead to the higher rates of becoming overweight or obese for shiftworkers (2,3).