Well, I guess you've just got to make a call here. If you think that she loves you back the same way you love her, then you telling her that you like her size shouldn't have any negative effects.

My girlfriend is trying to lose weight, and I told her that I liked her the way she is. She respected me for being honest and she loves me enough to still stuff herself every once in a while just for me, but she still wants to try and lose weight, and I support her in that. I'm not saying that your relationship will be as mutual as mine is, but I don't think that telling her is going to be the end of the world, unless she thinks that you *only* love her for her weight, which you've assured us isn't the case. =]

Once again, I seem to be rambling, so take this as you will, and I hope it helps some tiny bit.

Well, your first option is to tell her you like bigger girls and see what she says to that. =P Maybe she just wants to lose weight because she thinks it'll make her *more* attractive to you?

Second option is to support her weight loss if that's what she really wants. I mean, if you love her as much as you say you do, I'm sure you'll still find her attractive no matter what she weighs, because unless you *only* love her for her weight (which I hope isn't true!) you'll still find attractive things about her. =]

Not very helpful, probably, but that's the best I've got for you, my friend. I'd say the first option is your best bet, that way you two can discuss it more openly.