This is a yogic trick that plays with satiation signals in the brain. Sit relaxed in a meditative pose. Inhale air through mouth, into the stomach, in gulps, as though drinking air. Belch it out.
Initially you may not be able to belch it, due to self-consciousness. But this is a rather harmless practice. And if you are not unable to belch, the air will in any case be eliminated through the regular channels. Do this three to five times when you feel untimely hunger.
Avoid: In polluted places or if having respiratory problems.
Benefits:
It tricks the satiation signal in the brain which triggers the need to consume food. Also tones the digestive tract and helps with most digestive disorders.
Also see: Yoga poses for hyperthyroidism