Knowledge: The correct teeth alignment, orthodontist is the right kind of doctor to ask for help. On the other hand, psychiatrists can support and cure overeating.

Conversation:
It's hard for me to handle stress sometimes. I find comfort in eating a lot but I know it's not good for me.
Oh, that's too bad. Overeating due to stress is sometimes considered an eating disorder.
Yes, I know. I need to correct this. Do you know what kind of doctor I should go ask for help?

Response: Hmm, psychiatrists are the kind of doctor that you should go ask for help.