I read this book some time ago and want to reread it but can't remember the name. It was a MM romance. A student studying nutrition needs a roommate to help with expenses. A new student who's family is well off moves in. I seem to remember he was very smart and a bit antisocial because he was so smart. The smart guy falls for the nutrition student but the nutritionist wasn't gay but in the end he realizes that he is love with him and they realize that they want to be in a relationship. If anyone knows the name I would greatly appreciate it.

Could it be "Blame it on the Mistletoe" by Eli Easton?

Yes, it was. Thank you for finding it. I don't know why but I always forget that it is associated with Christmas.