What I do on brevets is we stop about every 30 miles and I eat whatever I feel like eating at the time. That may be a deli sandwich, bananas, PB crackers, ice cream bars, just depends on what's available.
You can complicate that to no end and count calories with a stopwatch and drink Perpetuum and Spiz or whatever other stuff you care to glug, but you're not gonna fall over dead because you just ate regular food when you were hungry.
__________________
"be careful this rando stuff is addictive and dan's the 'pusher'."