Biblical Book of Daniel (1:2-20, and 10:2-3) refers to a 10 or 21 day avoidance of foods (Daniel Fast) declared unclean by God in the laws of Moses. In modern versions of the Daniel Fast, food choices may be limited to whole grains, fruits, vegetables, pulses, nuts, seeds and oil. The Daniel Fast resembles the vegan diet in that it excludes (fasts from) the consumption of foods of animal origin. The passages strongly suggest that the Daniel Fast will promote good health and mental performance.