What should I tell my girlfriend?

We’ve been together for three or four months now. We have a great past of communication and I know we can talk about anything, but right now I’m at a loss of what I should tell her.

Forgive me if this comes off sounding piggish.

I like my girlfriend’s physical appearance now, but she’s told me that she lost a lot of weight. I never knew her back then and I’m happy with her weight now, so I didn’t see any need to further the issue. Last night I happened to see some pictures of her on facebook from when she was heavier. My first emotion was repulsion and that kills me. I don’t consider myself a very appearance driven person and I really do like her for more than her current appearance.

I’m so ashamed that thats what I thought first and now I keep seeing those images in my head. She exercises a lot now and she’s said she likes the weight she’s at currently, so I don’t think she’s ever going to return to that weight

The question is, should I even tell her that I’ve seen the pictures? I feel like I need to say something because we’re pretty open about things and it’ll probably be clear that I have something on my mind. I’ve thought about telling that I saw them and that I’m proud of her for losing the weight… I just don’t know.

Any advice would be appreciated.