Cortisol

Chronic stress triggers an ancient response that results in the release of cortisol into your bloodstream. Cortisol raises your blood sugar, which increases fat storage in your belly. So stress ends up increasing the size of your belly.
 Chronic stress contributes to fat accumulation through increases in the production of cortisol and, by association, insulin. Not only does insulin help you store fat, but it increases your appetite. So you eat more and feel less satisfied, a vicious cycle. An increased appetite ups the chance that you’ll engage in “hedonistic” eating in the form of nutritionally bankrupt sweets. This results in further fat storage, additional inflammation, higher insulin demand and more hunger.
 So, the more stressed you are, the more you tend to eat.