Actually, we think it is best to have dinner at home, or at a restaurant or with friends or family if you feel like it. Work just isn’t the place.
Not often, but sometimes it could happen that you have to work hard to meet a deadline, or there is something else you have to do in the evening. In that case, order something to eat and enjoy it later. We don't have any hard guidelines about what is and isn't allowed, but if it's reasonable, you won't hear us complain.