No experience with suboxone, but after I c/t'd from opiates, I gained about 20-25 lbs. I've always been small, so I felt huge (even though others told me I looked "healthy"). I wasn't in a position where I could turn all that weight gain into muscle, and I wasn't at all comfortable with the extra pounds, so I cut out refined sugars, made sure my snack foods were healthy, and started eating regular meals instead of grazing. I also upped my water intake. Over the course of a few months, the weight came off.
Peace & Love,
Sugah