You can eat whatever you want, really. But you mmust count your sugar and your carbs. Count each sugar gram individually, and carbs breakdown like this:
0-4g carbs - Don't count
5-20 carbs - 1 serving
21-40 carbs - 2 servings
41-60 carbs - 3 servings
61-80 carbs - 4 servings
81-100 carbs - 5 servings
101-120 carbs - 6 servings
You are allowed 15g of sugar a day, and only 6 carb SERVINGS. So something that has 3g sugar and 21g carbs, would be a 3/2 serving. Something like string cheese is a 0/0 food. Most proteins are a 0/0 food.
My breakfast is two eggs with one laughing cow wedge, and two slices of bacon. This is a 1/0 meal.
This program also wants you to remove artificial sugars from your diet, such as aspartame and such.
I really recommend the book. It gives a good insight to the program. I got mine from the library, and ended up buying both books in a combo pack on Amazon. The second book is a pocket reference for foods, lots of people say it is very helpful.
Hope this helps!