Every time during the corresponding reception of the food, if it is possible, place in front of you  either really, either in the imagination something that you consider a delicacy, and firmly deny it in favor of pieces of food and a glass of water and may be vitamin pills, only to keep you soul inside the body. The black diet starts and ends inside the illustrated circle, with a quarter circle path of darkness (counter-clockwise motion and the sun) and an expression of your intention to form the next curse: 

(name of victim) Yes whether you are cursed! 

Repeat this curse to yourself every time you reject the food. The process will last two weeks - beginning with the moon and soon afterwards, and ending with a full moon. When the moon decreases, dark tide flowing quickly. 

This practice can be successfully hidden from your friends using simple apology for the diet. There are diets everywhere anyway.