I don't think it's any of my business and that it would be better to say nothing but another friend says that suggests I don't care enough about her (which isn't the case).
The boyfriend is very insecure, and encourages her to over eat so that she won't be able to go off with anyone else. I find this quite sinister. He's also very jealous of anyone who spends time in her company.
She now seems to me like a shadow of her former (independent, happy) self.
However, I think she must know the negative things about him aren't healthy and that for me to point that out could make her angry with me. I really think it's none of my business who she dates and that I should say nothing....do you agree or not?