Would it be a deal breaker..

This is referring to a significant other. The way I read it a person you are in a committed relationship with. Why would you get into a committed relationship with someone who's values you don't share?

As far as food, no, it's not.

My husband has a major sweet tooth. I'm happy to make him goodies (I'd rather make them than buy them, at least I know what's in them?) and don't say anything when he gets into them at 11pm. He's an adult that can make his own decisions. If it was flat-out being a glutton and putting his health in danger, than yes, I would speak up out of concern.

However, if he was a lazy slug type, then yes, it would be. We're an active family and spend our time outside and/or doing something. We have our homebody days but I could not deal with someone that just wanted to be at home and sitting around the house all of the time, every day. He went through a phase of that and just about drove me up the damn wall.