I guess that was shift worker. I do shift work too and travel a lot. Simple answer is have a small travel cooler and take food with you. Boiled eggs are a staple, if you can handle them tins of sardines are perfect. Nuts, cheeses, cold cuts, some veggies, raw cauliflower, some berries & thick cream. I also take unsalted butter for my coffee. the odd square of 80% dark chocolate, for a treat. Have what you like as long as it is not sugar, (this includes fruit) and doesn’t contain any grains #NSNG the diet doctor site has some good graphics with ideas.