Women are stupid, you will need to be the judge of whether she needs to lose weight or not and convince her. Gok Wan finds that motorboating a woman helps her feel better about herself. Also stripping her naked in her favorite shopping centre, or putting half naked photos of her up all over town too & stopping strangers in the street when your out walking and asking if they think she looks good.
Serious tbh my gf is a size 6 and thinks shes getting fat, they will never learn and the urge to believe they are getting fat will never fade away!
The last thing you want her doing is messing about with her weight or its goodbye boobs and bum