Was with company for 32, about 30 of those years in feeders, almost all nights, almost always by choice, with about 5 years of sleeper thrown in, which will REALLY throw you into a physical spin.
Will just relate what worked for me and me only. You'll get all kinds of sure-fire hits, some misses, some rebukes on here but just remember, everybody's different. What works for Joe Schmooo may not work for you.
Started in the early days getting off work and opening the bars. Yeah, we'd get stupid at least once or more a week. By the time I got home, it was barely enough time for 8 hours sleep. Now, don't preach to me how wrong that was and how ignorant that was, I see that now and realized that a long time ago and quit. But what it DID for me and, again, ME ONLY, was realized that I did better staying up after work as long as I could and getting worn out and sleeping right up until time to get up/shower/drive to building/punch in and start. Oh, sure, most of the time I had headache and couldn't eat ANYTHING for fear of throwing up but maybe that kept me awake fairly fit as far as weight is concerned.
Once I quit that lifestyle (again, many yrs ago so don't chastise me), I would get off work, go shopping, go the the speed shops, come home and work on cars, watch stuff I had taped, anything that would keep me awake til just long enuff to get about 8 hrs sleep. Would eat right away after I punched out and nothing again til bed. No special diet, just anything. Would have one coffee during run, at the start, and no more. Water the rest of the night, and again, not so much that would make me get up every 2 hours during my sleep. No eats during run, either. Would rather drive hungry than eat some wrong thing to make me sleepy.
Sleeper, same thing. One coffee, eat at first of drive stint, water the rest of drive, switch, get into sleeper, watch movies or other stuff til just enuff time for 8 hours sleep.
Many drivers here go to bed right away, get up 3/4/5 hours before run and are exhausted half-way thru. Hmmmm...I wonder why? Could be you're maybe up half a day even BEFORE you start? They go out to eat, cut the grass, wash the car, whatever before they start work. I can't do that. Gotta do it after.
Kept physical condition almost the same during my career. The last few years it kinda fell apart, tho, cuz of some surgical issues. Retired now and still trying to get conditon back, but at least am alive and enjoying being gone and not sorry for all the nights.
Carryon.