Abstaining from food.

Moreover when ye FAST, be not, as the hypocrites, of a sad countenance: for they disfigure their faces, that they may appear unto men to FAST. Verily I say unto you, They have their reward. But thou, when thou FASTEST, anoint thine head, and wash thy face; that thou appear not unto men to FAST, but unto thy Father which is in secret: and thy Father, which seeth in secret, shall reward thee openly. ( Matthew 6:16-18 )