How do you lose weight when you have fibromyalgia? Before we can answer that question, we have to back up a step. Tami suggests that a lot of people start with the wrong question. They start with the question of, How do I lose weight? because that’s what we care about. That’s what we’re worried about. But if we don’t understand why we gained weight in the first place, then we might not be doing the right things to get the outcome that we want.