I've just started on this but it's making a lot of sense to me and I'm finding it pretty exciting.
His main focus is on convincing yourself, on a deep level, that it's safe to be slim. He says that we make ourselves fat for reasons -- even if they don't make logical sense, they make sense to our bodies. He uses visualization and destressing techniques, among other things.
It's a little similar to the setpoint diet of a few years back. The main thrust of that one was eating when you were hungry and not otherwise. But Gabriel's method is to make your body do it automatically.
I heartily recommend that you get the book and give it a try.
Onederland by July
Live in the sunshine, swim the sea, drink the wild air. ~ Ralph Waldo Emerson