There is one very rare exception to that which is one group of psychiatric drugs which as a side effect severely mess up the body's fat storage, so you end up preferentially creating fat rather than supplying the body's actual needs. However, they are incredibly rare because the harm of the side effects is so severe, and the only alternative treatment is sedation or a padded cell (IIRC only a couple of thousand people have ever been prescribed them worldwide and they spend their short lives in inpatient mental facilities, so no one you meet can use that excuse).