Eh... I don't know that, I think telling the truth is the best option.
I mean when you lie to your kids about that kind of stuff and they grow and learn the truth, then they start to wonder, what else is a lie?
Also I think if people ask a question they deserve a truthful answer, like for example "Does this dress make me look fat?" Sure you can say "no it doesn't" to avoid a conversation about it, but then she isn't going to ever hear the truth.