Fast on Ekadasi days or live on milk and fruits only—Sri Swami Sivananda 

Commentary:

Ekadashi falls twice a month according to the Hindu calendar. You can fast on these two days or on any one day in every fortnight (i.e. two days in a month). You can fast every week also on a fixed day. If you are unable to fast completely, take only fruits and milk. You should spend the period of your fast with your mind fixed on God. If possible, observe vigil the whole night and do Japa or Kirtan (God’s names set to music).

Fasting purifies your mind. It makes your love for God intense. It controls the habit of over-eating and your inclination to eat tasty foods which are not always good for health. It overhauls the organic systems related with the respiration, the circulation of the blood, the digestion and the urination. It destroys the impurities of the body and eliminates the poison from it.