Let's pretend that for some reason, you can eat anything at any time without consequence. No need to worry if you're going to get fat, have high blood pressure, monitor your salt intake or any of that crap. You get what your body needs to stay fit and healthy no matter what you shove down your gullet.
It's probably due to fancy new technology that allows us to make unhealthy food healthy, or change the way our bodies process it with nanobots or a pill, or some other wondrous marvel.
You still need to eat something to feel full, but it doesn't matter what it is or contains.
What delicious food would you eat on a regular basis?
Would the standard meal archetypes change at all?
What do you think would become new regular breakfast/lunch/dinner items?
Would the fast food / delivery / drive thru services change drastically?
Or would you just eat plain food that tasted like nothing to sustain your life and give it no more thought?