Fasting is used to cleanse the body. It contributes to Tandurut’s mental and physical development. There is no set rule for this. There is a custom of fasting in many ways in this culture and heritage.
However, both technically and spiritually, fasting without drinking water is preferred. However, fasting by eating fruits cannot be considered harmful. You are free to sit as you find most comfortable. It should primarily be planted with grain. Aside from eating, you may consume fruit, salad, and water.