Food magazines and advertisers know it: looking at mouthwatering images of foods often triggers the urge to eat. Blame that craving on a hormone, suggests a new study featured in yesterday’s issue of Cancer Research Update.
The study looked at a hormone that has received a lot of attention lately in obesity science circles: ghrelin. The hormone is recognized for stimulating our appetite. Ghrelin levels increase before meals and decrease afterwards. Circulating ghrelin then travels to receptors in the hypothalamus that are involved in appetite regulation.
This study collected ghrelin blood levels from 8 men every 10- or 15-minutes from before breakfast until after lunch during two sessions. Between meals, the well-fed participants looked at images of tantalizing foods during one session. A week later at the next session, the men looked at images of everyday, non-food objects, like a pair of shoes or a bike.
In the 30-minutes after the men looked at both sets of images, their ghrelin levels were higher after seeing the food images then the non-food ones.
To see how ghrelin stimulates appetite in the brain, here’s a video related to a 2008 study related to ghrelin stimulating our appetite.