Eating well, staying slim

Just bought this book, 'Eat well and stay slim' and am loving it. French nouvelle cuisine written by Michel Guerard who has a school for healthy cooking. It's a book which initially requires time to prepare sauces and to adopt a new way of cooking/eating but so far after an initial days prep, seems to make the rest of the weeks cooking pretty quick and easy. I like to experiment with food so this suits me well.
Anyone else got any similar books they've liked that have bought a sea change on in their cooking eating styles? I'm curious to hear of books with a very definite science/nutritional basis to them.