Hahahaha! What an awesomely impossible thing to do. First, you'd better be close to this girl.
She needs to know you care about her as a person before you start making personal suggestions. Second, if you are not in top shape yourself, she won't enjoy the double standard. And third, don't attempt to imply it indirectly.
If you have something to say to someone that is potentially hurtful, never attempt to joke about it or imply it. One possible way if you are not in good shape is to start talking about how you are concerned about your health and are going to be cutting back on eating and working out more. Eating tends to be a social thing, so if you two go out to eat and you pick healthy food and drink, don't finish your food, and don't order dessert, she will probably follow suit.
When you exercise, you could invite her along and be sure to keep at a pace she can keep up with. Thank her for coming and helping you keep on track. If you are in good shape and do make good eating and exercise decisions, then you probably will just have to talk to her.
Make sure you are doing it for the right reasons: because you care about her. Tell her that you are concerned that she is not taking care of herself and you want to help her make decisions that will keep her from health problems later on. One exception to all this is if she is in a career that requires her to be thin: modeling, ballet, television, etc.In those cases, giving weight advice is appropriate for people involved with her career: her boss, supervisor, co-workers, etc. Otherwise, stick with advising by example, and if that fails, talk to her.
Don't joke about her weight or imply she is fat. When you decide to say it, say it politely and kindly.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.