As a young female, I have a very different perspective on food shops. For me, they're calories to save money. I buy the cheapest calories I can since food is one of my biggest expenses as a gluten-free person.
Try carrying pre-cut healthy snacks with you - carrots, celery, cucumber, nuts, etc, then you can munch on the way there and be a little full. Don't be afraid to take home leftovers or even only eat a bite of one specific part to save it. I almost always save my fries and then add cheese or chili when I'm home for a whole second meal, like Irene said.
That being said, you should probably make an effort to schedule different kinds of shops. There are definitely more out there that would probably fit with your life and travel.