I like the quick easy doesn't require a refer on the tail such as PB&J in a wrap or PB&J with sliced banana, or honey. Or there is that bag of tuna if I need that protein fix, also carry fresh fruit (apples, bananas to curb that immediate hunger need). I'm one of those always eating (border line Hypoglycemia). Basically always eating (breakfast, snack, lunch, snack, dinner, late night snack etc and snacks btwn snacks...). As for fluids and staying hydrated typically carry a camelback, insulated thermos/tall 1 gallon cooler and if needed larger container of water. Now on the other hand if were full on camping/traveling for days on end we toss what ever will feel like eating in the refer in the Lance camper for the period we are out on the road.