A good rule of thumb is to give yourself at least 24 hours to decide if buying something is a need, or just a random impulse purchase, by “sleeping on it.” That allows enough time for your impulse to settle down so you can approach the purchase with a clear mind if you really do need it.
Anorexia is the eating disorder you are looking for.
The top one is the answer
Tobacco is considered a gateway drug.
Speed up the treadmill and make sure to drink enough water.