A friend of mine who took lithium gained almost 100 lbs. Another friend who is anorexic will only take lithium because it's not a weight gainer for her. Now, I pay close attention to side effects after ruling out a well rounded diet with cardio, strength training etc. On seroquel I did a lot of damage to my back. The more weight I gained the more obsessive I was with exercising. Carrying all the extra weight while speed walking 30 miles a week was stupid. My metabolism is also screwed up from having issues with ED's and hormone levels.