What Is Starvation?

Contrary to what many people believe, fasting is not starvation. Starvation
begins when abstinence is continued beyond the time when the body's stored
reserves are used up or have dropped to a dangerously low level. During the
fasting stage the body supports itself from the stored reserves within its
tissues. When food is eaten at normal intervals, the body stores sufficient
amounts of nutritive matter to last for a rather lengthy time during later
periods of abstinence. Even thin people carry a reserve of nutrients in their
tissues to tide them safely over a period of fasting.

The body will not starve or in general even be hungry while fasting because it
is ―eating.‖ It is consuming the substances the individual consumed last week,
last month, and last year that have been converted into body tissue. In fact,
the symptoms of hunger generally disappear by the second day of the fast.
This illustrates that the body has entered a fasting, and (lean) tissue-sparing
metabolism. Of course, there is a limit to the body's reserves. When they have
been used up, specific symptoms occur that indicate the fast should not be
continued. The time required for a fast to reach completion varies from
individual to individual. The trained physician can easily denote symptoms that
indicate the ending of the fasting period and the beginning of starvation. In the
vast majority of fasts, the physician will end the fast many weeks before the
nutrient reserves of the body have been exhausted. The average individual (not
overweight) would have to fast approximately 40 days or more to exhaust
nutrient reserves.

Such a prolonged fast is almost never recommended and, therefore, we are
not remotely considering the biologic processes of starvation during the fast of
average length. If the fast was continued beyond the point when the body's
nutrient reserves were exhausted, starvation would begin. If not eating was
continued past this point, damage to the body and even death could result.
Most patients are fasted one to four weeks depending on their nutritive
reserves and the purpose of the fast.