Bod 4 God: The Four Keys to Weight Loss is the best book out there for Christian weight loss. It describes a spiritual program where faith is at the center of everything about the program.
While it does not prescribe a specific food category, it contains principles for permanent change, like drink in ounces half your body weight in water each day. (Start small and work your way up if you haven't been drinking hardly any.) It also recommends shopping the perimeter of the super market for living food, versus heavily processed carbs on the interior aisles.
Interspersed within the 12-week program are stories of big losers who dropped major poundage and kept it off. They provide in-depth stories of how they did it and why they were successful.
Motivation is a key to the success of this program. It encourages us to find a team of losers and let them help us find a program that is really about permanent lifestyle change.
Can't say enough good things about this book or the program. I read a previous edition and participated in the program. I lost sixty pounds and kept it off.