I too also gained alot of weight right before I got sick. I really had to try to lose weight. I am almost 25 and I was 6'3 250. Leading up to the problems that I was having I probabaly gained 20 pounds in 2 months. I have a hypothethis your body probably gains fat to store heavy metals so they don't go elsewhere like your brain nerves etc. Makes sense, also makes since why I "dumped" so much metal in my body when I INTENTIONALLY lost weight.