The question is ... is he happy with the "non-variety"?
Or are you "fixing" something that ain't broke?
Perhaps consider a thermos ... then you can send something hot with him ... stews, soups, etc.
To keep things cold ... freeze bottles of water or juice ... works as an ice pack, then becomes a cool drink for him to enjoy. (just be sure to not fill to the top, to allow for expansion when frozen)