What a fabulous question! I"m so glad you asked it. I don't come from a background of having a diagnosised eating disorder but i did see my mom, go from weight watchers, to Overeaters anonymous, back to weightwatchers, then to the cabbage diet and on and on and on. I think she suffered from depression but if you asked her why my dad cheated on her, she would say her weight, and that was my impression at the time as well even though i know now there were alot more to it.
I think the majority of girls/women have a distorted body image, I did a neat exercise once for a health class in college, we had to draw our bodies as we thought we were on a big peice of paper, then tape the paper on the wall and stand in front of it and the teacher used a different marker to trace our actual bodies, Everyone over estimated and drew huge people but in reality we weren't that big. That has stuck with me for so long. I"m not a size 2 but i am a decent size. Could i be healthier? heck yeah but i'm not going to get that way by obsessing about it.
Anyhow, my first suggestion, is to try to cut out saying skinny or fat. The aren't good decriptors, say the large apple, instead.
second, i've heard alot about the Dove project using larger models you might try their website, if i have time i'll google it for you, i think beauty or inner beauty might be part of the name of it.
found it its' at www.dove.us and it's the campaign for Real Beauty. They actually have some activities on the website that look pretty neat. The age range is 8- something but i took a quick look and some can be adapted for your dd age. This was my fav. At the dinner table or at bed time you can play a game were every one has to give someone else a compliment, not just a physical one, but more positve behavior. I"ve also heard of a variation where everyone tells one good thing and one not so good thing about the day, so kids at a young age feel comfortable talking with you about anything on their minds.
Third, start looking now for someone to be a mentor to your daughter to sort of help with this topic, maybe an aunt, one of your friends, girlscouts or some sports related coach, but be super careful that they will promote the right values, that healthy bodies are beautiful bodies.
fourth, be careful of what you say and do around her, if she sees you getting tense she will pick up on it. Iknow that might be hard. Is there someone that has helped you in the past that might offer some on going support. Since i'm 100% sure you are not the first women to try to break this cycle and do better for their own children.
Big Big hugs, I wish you and your daughter the best! This is a hard topic, one i think women really need to be more open about.
edited: Wait Wait Wait, I just read your SWH and the responses after mine, I think some of them may have been a bit defensive and not super caring, and i know you are sensitive to this which is why i tried to be super nice. But PLEASE don't tell me that you think it is age appropriate to look at a fat person and tell your 4 yo not to ever be like them. I don't think that is even ok for you to tell a 16 yo!
focus on telling her to be healthy is much much different than telling her not to be fat. That isn't avoiding the subject! that is being a kind decent non judgemental person.
Should i go around pointing out super skinny people to my 6 yo and telling her never never to be like them because they are all bulimic and bulimia is a sign of a mentally unbalanced person. Does she need to know that? not at 6 she sure as heck doesn't. When she is older you can tell her there is a WHOLE RANGE of unhealthiness surrounding weigh BOTH overweight and underweight. But it still comes down to HEALTHY!! NOT about being pretty and not about being loveable or not. sorry I would just love to live in a world where people judged each other on behavior instead of looks.