"In a 1997 article in the British Medical Journal, Michael Peel, senior medical examiner at the Medical Foundation for the Care of Victims of Torture, cites well-documented studies reporting survivals of other hunger strikers for 28, 36, 38 and 40 days"
"From a medical standpoint, most agree that human beings can survive for up to four to eight weeks without food, although some people in history have fasted much longer."
"Most commentators note that Food is not usually urgently needed in survival situations because a human can survive for several weeks without it"
"Although you can live several weeks without food, you need an adequate amount to stay healthy."
sources listed below, respectively.