My daughter, who will be 13 in 3 weeks is overweight. I send her healthy food for lunch and provide her with good sized healthy meals for whenever she is at home, but if she goes to her Dad's on the weekend or to friends houses, she eats lots of food, usually junk if it is an option.

I have tried exerciseing with her, making it up to her to watch what she eats, getting angry at her, being nice and sympathetic, everything I can think of.

Her dad and I don't talk - he doesn't like me, but I am considering sending him a letter or text to see if he will discuss this with me, or at least tell him of my concerns. His dad has diabeties, and his mum just passed away (she was over 100kg), so I don't want to say anything too soon to her passing - maybe in a month or so when it's not so raw.

Any ideas?