Autophagy occurs when the good cells in the body actually eat the bad/deformed cells in the body. Autophagy became interesting in the area of cancer, because it became a method to combat certain types of cancer. When you are fasting for a certain period of time, autophagy is turned on. Why would good cells want to eat bad/deformed cells you might ask? Your heart health, liver and kidneys all benefit from autophagy. Autophagy is activated when the cell is starved of amino acids. When you are fasting, autophagy is turned on.