I'm Sorry I Have Little Information...


Possibly a Darkfriend
I am looking for the title of a book I read many years ago when I was just a kid...I cannot remember much about it other than a few key things.

The 'good' characters could fly
They were fighting against people who made everything artificial....including food. One bit I remember when a man and woman were captives, they were given fruit juice, and the woman was disgusted to find the passion-fruit pips in it were plastic.
The girl who was brought into the world did not believe she could fly at first and was given a feather to help her believe. One part had a character claim they heard someone coming, and to go "into the trees". Naturally the girl forgot to grab her feather and flew without a problem.
The last part I remember was when this group were trying to rescue the aforementioned captives, and one of the children was given a bag of candy by a drunk one of these fake food people. The coating on the candy, a white powder, was perfect for disguising themselves to look like the fake food people who had white pasty skin.

I again apologise for not remembering more, but if anyone has read this book and knows the title, please let me know. Thanks.