How do I encourage my girlfriend to develop healthier habits?

I met this girl online bout 8 months ago, she's cute, we ended up Skyping for like 6 hours every weekend because I'm stationed elsewhere at the moment. I went to visit her for a few weeks. This is where I started to notice her lifestyle. She doesn't seem to have any willpower and it kind of annoys me.

While I was there she was constantly pressuring me to go eat out with her, and she doesn't seem to realize how unhealthy she eats, and to be blatantly honest, it kind of shows. On top of that she's always broke yet she will go eat McDonald's every day rather than save her money.

I feel like I'm starting to lose my attraction to her because she just doesn't seem to care, either about her body or about her finances. I've been as subtle about it as I can be and I even got in an argument about it when I was there but it just doesn't sink in to her. She always complains about not being able to pay bills and saying "birth control is making her fat" and I just don't know how to inspire her to do better.

On top of that, she's fallen head over heels for me and is scared I won't feel the same, so of course I feel bad because I wish she'd change. I really like her but I don't know what to do I know that if she keeps making excuses for herself she'll never develop the discipline to workout regularly and learn how to manage her money.