Perhaps of all the holy days, Atonement is the most difficult to keep because of the demand to afflict ourselves by going without water and food for 24 hours. Physical fasting provides insights to a parallel spiritual process of cleansing and removal of sin. Intermittent fasting, gaining popularity in weight losing organizations, is a process that triggers a burning of stored fat and consuming damaged cells after a period of 18 hours or more—either using strategic phases of eating or fasting. Autophagy, according to healthline.com, is a natural, self-preservation mechanism whereby the body removes damaged or dysfunctional parts of the cell and recycles other parts to cellular repair" in other words, the body begins to cleanse itself by destroying or eating damaged cells while rebuilding ones that can help heal the body. Fasting on the Day of Atonement depicts the cleansing and removal of our sins through the blood of Christ. We are given the mandate that we should forgive others who owe debts against us—a mere pittance of the unpayable debt for which we have been forgiven. Our High Priest commands us to "let go" of the grudge we have for people who have grieved us, enabling us to wipe the slate clean, lightening our burden.