Norm generally answers very fast. He must be off-line at the moment. So here are my 2c 🙂
In the context of FTD we consider dietary fiber AND sugar alcohols as carbs. So, net carbs = total carbs – dietary fiber – sugar alcohols. That’s for instance how Norm’s FP calculator works.
However, outside of FTD things can be quite different. Most of the time, I seem to remember, sugar alcohols are not listed as carbs. Dietary fiber seems to be part of carbs in the U.S., whereas it isn’t where I live (Austria) and apparently neither in UK.
Let us know if this helps, and especially how you do following the FTD. Be aware that a weight loss in the 1st week of low-carb diets is a known and temporary phenomenon. But do mind the calories when you change your diet 🙂