I too would like a specific entry for Sugar, it seems odd that it was omitted from the format.
What I have been doing, when creating custom foods, is using "Alcohol" as my sugar. Since I rarely drink, I rarely use that category so filiing it in as sugar is no big deal. This allows me to track sugar in this fashion.
When using existing foods it becomes more problematic, but then I will often convert many existing foods to custom foods anyway as it gives me more control over the content, I feel I can be more accurate this way...