What is the best suggestion to cut out fast food daily?

I currently work 8am-630pm M-F and I have this terrible habit of eating out for dinner most of the time everyday. I don't gain weight but I'm not gonna say I'm in the best shape either. What are some suggestions as far as cutting back or cutting off fast food as a quick fix? I realized when I don't touch fast food for like 3 days I already feel like my pants are losee or something around my waist has shrunk. And yes I'm basic as hell at cooking. A work in progress.

Thank you.