As far as I know Weight Watchers have these points where your food intake and aerobic workout all compute into a set amount of points you're supposed to consume per day (working out increases the number but only on a weekly basis, so be careful).

You should consult your counselor, and see if perhaps you have too many points in your daily intake, and taking one or two off could make all the difference (or adding exercise). Don't do this on your own though, because not having enough points could also lead to a halt in the weight loss.