Go by how you felt at the start. If the first dose hit you hard with side effects, take it slow. I saw hunger return after four weeks on 1 mg and went straight to 2 mg. Even then the effect is milder than the first week, so the body seems to adjust.
Been on 1 mg for six weeks now. Dose day is tomorrow and the food noise has come back strongly this past week, so I am eating far more than before. Early on I could barely manage 600 calories; lately 2000 feels easy. Should I move to 1.5 mg or 2 mg, and how do people decide?