<human>: Let me start by saying that I love my girlfriend just how she is, she is wonderful and I would never want to change her for a shallow reason. My girlfriend has always been very thin, but I'm starting to get concerned.

I first noticed about two weeks ago that she looked a bit different to me. She was putting a shirt on and each of her ribs were extremely defined. I just wrote it off because, like I said, she's always been thin and the outline of her ribs have always been somewhat visible. But later that day we were cuddling and I realized by feeling that her ribs were seriously jutting out, which is why they looked different. I also noticed that her stomach was basically concave - the only term I can think to describe it. 

I didn't want to bring it up randomly because for all I know it was just natural and I didn't want her to think I have a problem with her body. But I started keeping an eye on her and she's definitely been eating very little. I asked her about it, she just denies it or says she isn't hungry.  I don't know if I believe her... She has insecurities, but her weight has never been one of them so I don't know if that's the problem or what would be. 

Has anyone else had this happen with a partner? Is it possible that her body is just changing and causing her to lose weight? Is it healthy to have ribs that jut out and a concave stomach? Again, I love her how she is but if there's a problem I want to take care of it. Thank you so much for any help.

Can you provide a brief rundown of the text in within 3 sentences?
<bot>: My girlfriend is eating less and is extremely skinny, I don't know if this is healthy or if I need to do something to help her