Hi maidmarian,
Yes I have to admit nuts and seeds are one of my little passions as far as treats go and at certain times of the day I can often be seen rifling around the cupboard looking for a handful of nuts just to amuse my taste buds for a little while.
But like Andrea has said it's good to be choosy about what types of nuts you eat, pecans and walnuts are indeed nuts that contain some of the lowest amount of carbohydrates but top of the list of those to stay away from particularly this time of the year are roasted chestnuts, they contain anything up to 20 times as many carbs as pecans and walnuts do.
As fro xylitol, well out of all the synthetic sweeteners, that is probably the one that gives us the least problem particularly in its purest form but if you have pets do remember to keep it away from them as it can be extremely harmful if not deadly for many pets but more so to dogs,
Hope that's useful,
Mark