The neurotransmitter in question here is Serotonin.

And people affected by eating disorders have less of it than other people.

Turns out a bite of hamburger has the same effect as Prozac

Serotonin deficiency makes you feel like you’re the bottom of the pack ... like you’re a victim of society and that you will never rise the ranks and that your best shot at making it is to be subservient to the power and treacherous to those immediately above you