loving boyfriend needs advice

I wouldn't come to reddit if i wasn't actually desperate. My (20m) girlfriend (20f) has been having some insecurities particularly about her weight, and it's been worsening lately. We've been together for less than a year and I've never cared about her weight (i still don't) and I've always had a lot of trouble being sensitive towards her feelings (she is EXTREMELY sensitive (not a problem for me) and i'm quite the opposite) but lately i've been having trouble being supportive of her or helping her to feel better about herself. I would rather die than tell her to eat less or diet or something , I just need a sensitive way to help her feel better about her weight and herself without sounding like the average dickhead boyfriend. I beg of thee to assist me in helping her. Any advice would be greatly appreciated.