I used to work near a food market where there were dozens of independent good stalls that were setup to serve working people lunches. The food was still fast, but a lot healthier, and you could go to one place and have a wide choice of options.

There’s a lot of possibility in between hunting and eating fast food. Buy some healthy food at the grocery store and pack a lunch to bring with you.

There is a formulation, a sugar/fat/salt ratio that the majority of people will find satisfying. Fast food tends to optimise this way. It's why, for example McDonalds burger buns are quite sweet.

But I don't know whether dopamine is the pathway responsible.