I am also single, and cook for one (well, unless you count my two dogs, who always think they should have at least a taste of what I'm cooking!
I have made some of the recipes in the book, and when I do I make them just as they are. Then I have leftovers for then next day or two....cooking is not my favorite activity, and if I can get out of cooking every day I'm a happy beacher!! Some days I just use the acceptable foods list and concoct my own meals, without following any recipes.
Like Franny said, most people don't follow the menu laid out in the book. As long as you stay with the acceptable food list, and keep your portions (of meals and snacks) appropriate, you'll do fine!
Good luck!!! And be sure to come here to post often, this is a great place for support and friendship!