This probably sounds familiar: You stop by your office break room and notice some chips or cookies lying out—leftovers from a catered lunch. You’re not hungry, but you decide to have a bite or two. By the time you’re back at your desk, your stomach is screaming for more.
What’s the deal with that?
Even before you swallow a bite of food, taste receptors in your mouth start “talking” with your brain and stomach—letting them know food is on the way, says Belinda Lennerz, M.D., an endocrinologist and nutrition researcher at Boston Children’s Hospital.
That leads to hormone shifts and other metabolic changes that help your digestive system prepare to handle a big influx of food, Dr. Lennerz says. (One example: Your insulin levels tick up in order to keep your blood sugar from climbing too high post-feed.)
All this is good and necessary if you’re taking down a whole meal. These preparations keep your body in a happy state of homeostasis, Dr. Lennerz says.
But in that break-room scenario—and in many other snacking situations—your body doesn’t know you only intended to have a bite or two, she says.
Your gut and digestive system react as though a big meal is on the way. The resulting drop in blood sugar can shoot your hunger through the roof, Dr. Lennerz says. That can send you running back to the break room to pound those cookies and chips by the fistful.
What can you do about all this? Follow these three snacking rules: