<human>: My girlfriend (25) of 4 years has always been curvy and I (M28) like that, but over this last year she's put on a bit more weight and her belly has gotten quite a bit flabbier. Personally, I'm still sexually attracted to her, but it is a little off-putting. I think it's affected her worse though and I know this weight-gain has made her more self-conscious, and affected her self-esteem and her libido.

Work-wise, this year has been very  on-and-off for her, and she and I are moving house at the moment (we've lived in a shared house for just over 2 years) and this combined stress has compounded some of her insecurities.

She's reluctant to talk about it but when she's mentioned it (only ever briefly) I've done my best to explain that I think she's beautiful, that and that if she wants, we can change our diet etc.

I want to have a full discussion with her about how she's feeling about her weight and self-image, and how we as a couple can work on that, but I'm really not sure how to go about it.

Summarize the given text in a few sentences.
<bot>: my girlfriend has put on weight. It bothers me a little, but it's harming her self-esteem, and that bothers me a lot. I want to help but I'm not sure how.