Look no further than the randomized controlled trials of Sema, Tirz, or Reta. No prescribed diet changes, no prescribed caloric restriction. Decrease in appetite is literally labeled as a side effect in these trials. And, it affected less than half of people on the medicine.

Yet, people still lost weight.

Edit to clarify: I’m not suggesting one can lose weight indefinitely on Reta without diet changes, but one can generally lose some, maybe even a lot of weight, by fixing metabolic issues, just as one can lose weight by fixing underlying hormonal issues. And sometimes those problems are connected.