BTW, I think the silent option applies for most women.

Women don't forget. I can't count the number of times that I said something totally offhand and harmless, and they'd mention it a week later. It's always one of those "Oh my god, this? Now?" moments.

If you're determined to make her lose weight, the best you can do is do a lot of sport yourself, and always drag her along. Pick something you both like. Don't take no for an answer. You're not telling her she's fat, you just like her company. And don't tell her she needs to lose weight... she won't forget.

Of course, exercise and proper diet go hand-in-hand, so be prepared to cook for her too. I guess this option only applies if the relationship is intimate.