I cleared some space on my bookshelves, sorting through the books I no longer wanted to keep. I came across several "diet" books I used now and then. One book recommended a person keep track of their portions; allowing so many portions of certain food groups to stay within certain caloric ranges for the day. Another book recommended keeping track of ratios and percentages of fat, carb, and protein. (I'm not even sure why I hung onto that book since it was far too complicated for my everyday use.)
Anyway, as I took those books off the shelves, I tossed them into the "donate" pile without so much as flinching. I've hung onto them for years because there were parts of them that worked for me (with the exception of the afore mentioned ratio/percentage book) and at various times of my life I would pull them out and try again.
But now, I feel like I truly have found a way of eating that works for me, and I feel confident to toss those books. It's a good feeling!