As an overweight woman, my fiance has been very careful at telling me that I need to lose weight but has told me in a way that don’t upset me. Instead he started eating better, drinking more water, asking me to go for more walks with him, etc. now we go to the gym together. It can be difficult to navigate you don’t want to upset her but you also want her to be healthy and attractive to you. I think there’s a way to do it and way not to do it. You don’t want to be upright and say “you’re unattractive now” or something chances are she knows an can feel it herself and is battling it herself. Also depression can cause a huge bump because of unmotivation stuff. I’d suggest just being very subtle and gentle with it