Not at all. However it is worth bearing in mind that many sugar substitutes for the purposes of dieting are not suitable for diabetics (according to my educator). One of the tricks is to arrange exercise right after the treat that you wish to consume (or rather, within the period of time that you know your glucose levels will peak). By making sure that your sugar that you consume is used up right away, you have less problem with it.
I wouldn't recommend doing this all the time, but it helps when the cravings set in
