DS2 (14 months) had an epic stomach bug over the weekend and we think he lost about 3 pounds. We were so sad that his little chubby tummy looks so slim now. I want to fatten him back up. He doesn't care for avocado but he does like cheese and milk so I've been trying to get a lot of those in him. Should I try pediasure or anything or just let nature take care of it?