When the Moon is cold and slender, stand beneath her, wearing only white and silver, and chant:

"I make my vow to fast until,
This crescent Moon shines round and full;
While she waxes, let me wane.
I must lose, that she may gain.
While she grows, take silver wine,
silver water, silver milk,
And bread like snow or linen fine,
And fish as clear as ice or silk,
but only these, and less of all
than you would wish to feed her well."

Limit your diet to the foods mentioned in the vow.

A Word of Caution: This vow is intended to improve your willpower, and strengthen your resolve. It is no substitute for healthy eating and exercise.