It's not my quote, but it is totally applicable here:

"If you do what you've always done, you'll get what you've always gotten."

This is a Way of Life, not just a diet. If you really learn how to feed yourself properly and get habituated, and learn about the true variety available, I see no reason this WOL is not sustainable.

Of course if one is only trying to lose a few pounds, one might not have an opportunity to BECOME habituated before reaching goal.