The key for reading any carb count is to subtract out fiber and sugar alcohols. So if you had a wrapper that said:
Total carbs: 17g
Fiber: 10g
that means there are only 7g of "countable carbs" in that item. Eating fiber is like eating cardboard. it goes in one end and out the other and sort of "cleans out" your system as it goes. Think of it as eating sponges. You aren't digesting the sponges, they are just scrubbing out your intestines and such as they go. That's why it's so great to eat fiber, it helps to keep your insides clean
In a sort of similar way if you had a wrapper that said:
Total carbs: 17g
Sugar alcohols: 10g
that means only 7g of them are going to affect you. Sugar alcohols are specially modified items that taste sweet but that your body doesn't actually use. So just like fiber they go in, they go out and you don't gain weight. However, because of that, they can cause huge laxative problems for some people. As in you'll go running for the bathroom. So eat sugar alcohols VERY carefully at first to see how your body reacts.
