And you're just gonna change like that?! Your gf should not care about your eating habits, unless you're becoming noticeably obese, or you start smelling like curry. And if you smell like curry, well, good luck getting that smell out of your clothes and apartment.
This sets off alarm bells for me, because when a girl starts to change their guy like that, it means that she wants to fuck them over in some way before dumping them. It's a sign of disrespect. And it's a way of trying to emasculate you. If she says something about doing this and love, she's lying. I really hope this isn't the case with your situation.