i ate a shitload of those last year when i did a CKD diet and never had a problem. the DO have more carbs than 2g (glycerin, etc) but they are supposedly "non-impact carbs" meaning they don't have any effect on increasing your blood-glucose levels or insulin. some people say that they do increase liver glycogen stores, but it didnt' seem to have any effect on my fat loss while i was eating them.
of course everyone is different, and you'll have to try 'em for yourself and see how they work. personally i ate so many of them i can barely stand the taste of them now. their hazelnut, chocolate fudge, peanut butter & chocolate mint were all very good.