When she asks. Or when she raises the subject.
She is 22 and in university about 5 hours from home so only comes back for the big breaks.
She was always thin and fit but 2ish years ago she got depressed and in the course of dealing with that she began over eating and gained several stone over a short period which she has kept.
In her head she is still a thin girl so whenever she sees herself she gets upset and despairs. She is still actively dealing with depression and is doing brilliantly in spite of her mental health struggles.
She often says "I can't lose weight", "I'm hungry all the time" and I don't know what to say in response.
I've tried the positive comments and focus on other things. I've suggested quick and easy healthy food. At home I always cook healthy vegetarian food but I think she raids the cupboards between meals (probably healthy food, just too much of it and no exercise)
What are good, constructive and non harmful things to say in response to weight woes?