I was on Cymbalta and found no changes in my
weight due to that. But Lyrica did cause me to
gain weight rapidly
and without changing my diet. Once I stopped taking the Lyrica, though, that weight just dropped right off.
It can be really hard to exercise when you have chronic pain. I found swimming helped as it was gentle on my joints. I also found, through trial and error, that I was able to use an elliptical machine, even with bad joint pain.