Pacification - substitution is the best policy for this. Just like a smoker uses a cigarette for pacification or a baby uses a thumb, some people use food as a pacifier.
Hormone imbalance - hormones are responsible for many things going on in the body like reproduction, sleep wake cycles, etc. One of the things they are responsible for is metabolism.
Over eating - For this, the best medications are Phenteramine, Diethylpropion, and Phendametrazine. These medications are oldies but goodies.