Why do red light districts and great food come together?

I've always yearned to find out why red light districts boast fantastic eats. I wonder if anyone has carried out any sociological experiments to uncover underlying factors.

My dad says well because there's always strong demand, be it from locals and/or tourists. So with demand, comes the need for supply (of great food that is).

Maybe I should switch to a humanities masters, and propose this as my thesis.