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According to Deuteronomy 9:9, Moses did not eat or drink anything for 40 days.

When I was gone up into the mount to receive the tables of stone, even the tables of the covenant which the LORD made with you, then I abode in the mount forty days and forty nights, I neither did eat bread nor drink water.

Is this possible from the scientific point of view? My guess is that no water for that long time must be impossible. How about no meals?

{ asked by Fitri }


"Comment in passing"—the biblical term "40 days and 40 nights" or similar can be used to mean "a long time". Whether this is the case in any given passage would need to be understood, but is outside the scope of this question.

In any normal circumstance you'd be dead long before 40 days without water.

But hunger strikers regularly live beyond 40 days and purposeful fasting for that period is not unknown.

As an example of what this may do to the body, assume that a person fasting is largely immobile and can survive on a 500 kcal daily energy budget. Available calories from food are about 4 kcal/gram for carbohydrate, 5 kcal/g for protein and 9 kcal/g for fat. Start by assuming that body resources can return say 6 kcal/gram if "living off your own body.

Obviously there are many other factors to consider, and the above mass loss seems 'rather low' compared to expectations, but is an indication that energy availability is not the major factor involved.

This document—Adult Malnutrition in Emergencies—advises that hunger strikers experience "severe metabolic disturbance after 3 to 4 weeks" (ie 21 to 28 days) and death in 6 to 10 weeks (42 to 70 days). ir 40 days would be "pushing your luck".

{ answered by Russell McMahon }