gnaivah?

Question

I work for a company that reimburses me up to a certain amount of money for meals when I travel on business (which is frequent). If I don't use the travel meal allowance for the day, the reimbursement is lost to me and I cant "save up" the reimbursement money for a really expensive meal. If I do not feel like eating a meal during one of these travel days is it gnaivah if I purchase food "to go" to bring home, give to my wife or to eat on another day? I've seen others take home leftover food in a doggie-bag with the boss present and it was ok, but this is different maybe because of intention. Let me be completely honest here, I would be embarrassed to do this if my boss was traveling with me. Thank you for your help!