Can't believe I'm the first one...
But in all seriousness, it just sounds like one of two things. Either you guys just don't want the same things, or she is just going through a rough time and you need to be not only supportive, but patient. Life is a journey. Many people change many times as they travel through life. A relationship is a team that grows, changes, and thrives together. If you really love her and trust her deep, internal values, then maybe patience and understanding are in order. This is all of course based upon basically zero knowledge of the two of you on a personal level.
IMO it sounds like you're a bit of a dick, but again I don't know the back story. Is her working out something she has expressed interest in doing or is that something you are pushing on her? There is nothing wrong with not being a size 0 model, or being messy for that matter. To each his own. Just gotta find someone you are compatible with, typically, to have a good relationship.
Again, to be clear, I'm not judging you. But your OP definitely came off a bit dick-ish IMO.