Stabilized is fine, just not as many nutrients as the non-stabilized.
I have no experience with intentionally packing on pounds, I'm always trying to drop a few. From what I've read on CZ it's often much easier said than done. I'd recommend fats and meats and things like avocados but the body just doesn't store those calories like it does carbs, so it may not work. A quick search yielded:
Iodine has led some people back to a healthier weight. You might go over to the VWT Iodine Supp. forum and type "gain weight" into the search box, though I should point out that supping w/ Iodine is complex and takes time.