Admins rarely (if ever) check in to answer questions.
I have Premium but have not tried the PC version so my advice is limited. Premium does not let you add custom nutrients or sugar, per se. Nor, as far as I know, does it let you set a goal to gain weight.
What you can do, though, is track "anything" though you have to enter the data manually (if you were tracking "sugar", for instance, you'd need to add it up yourself and enter the data).
Hope this helps! If anyone knows about the PC version, please chime in.
47 M 5'8"
May 4, 2010...... 440? lbs. (Start FitDay Size 60 Jeans)
June 19, 2010.... 393 lbs. (First Weigh-in)
June 19, 2011.... 229 lbs. (164 lbs. gone in one year :-)
Current Weight... 185 lbs. (Size 36 Jeans)
Next Goal 169 lbs. (07/04/12)
Ultimate Goal 165 lbs. (12/31/12)
The best exercises for weight loss are Fork Putdowns and Table Pushaways.