There is no way to know by solely playing the game what lunches each spouse can provide without marrying someone and finding out firsthand. I going to assume that you are asking what the lunch box options are for each love interest.
Spoiler:
In both games, each spouse has a selection of about 5 meals they can provide. The possible meal list is different for each love interest. You get one lunch box per day at random from those 4-5 options. I am not sure how the level of the gifted lunch is determined; it might be random.
