Why does diet change a person's emotions?

Why does diet change a person's emotions?

It has long been no secret that dieters become a little more irritable than usual, because they are forced to deny themselves the consumption of their favorite treats. But recently, American scientists found that women who do not diet and eat their favorite treats choose romantic comedies to watch, and those who reduce their diet to vegetables and fruits choose thrillers and horror films.

At the same time, women who limit themselves to food become more aggressive. And people who eat their favorite foods show complacency and stress resistance.