<human>: Provide a brief overview of the text.

GF is 19, I'm male/20 and we've been together for 1.5 years.

My GF has put on a bit of weight since we started dating.  She's not overweight, but it is a weight gain nonetheless.  She has stated several times to me that she is "tired of being fat" and that she wants to lose weight.  I assure her she isn't fat, but if she wants to lose weight, she is more than welcome to join me in my workout regiment and diet (when I say diet, I just mean eat what I eat).  She refuses, and says something like "I hate working out."  She won't even take the stairs in buildings, including our apartment with the elevator that takes 7 minutes to arrive. 

She eats terribly.  She usually skips breakfast, and then for lunch she chows down on a bagel with three inches of cream cheese (okay I'm exaggerating...) and for dinner she'll usually have what I'm having.  After dinner though, she'll eat cookies, chips, freezies, etc.  She also never works out.  All this is worrying enough, but recently I've noticed her googling things like thinspo, thinspiration, Russian gymnast diet, pro-ana, and other worrisome phrases.  Sometimes I wonder if she's bulimic.

How can I talk to her about this?  She is very self-concious, and doesn't take criticism well.  I'm not sure how to approach the situation or how to deal with it.  I am very, very worried.
<bot>: GF has put on weight and has been googling things about anorexia and bulimia, and refuses to eat properly or exercise.  How can I approach the subject?