Survival skills
A human being can survive an average of three to five days without the intake of water. The issues presented by the need for water dictate that unnecessary water loss by perspiration be avoided in survival situations. The need for water increases with exercise.
Prahlad Jani
Two observational studies of Jani have been conducted, one in 2003 and one in 2010, both involving Dr Sudhir Shah, a neurologist at the Sterling Hospitals in Ahmedabad, India, who had studied people claiming to have exceptional abilities, including other fasters such as Hira Ratan Manek. In both cases the investigators confirmed Jani's ability to survive healthily without food and water during the testing periods, although neither study was submitted to a scientific journal. When questioned six days into the 2010 experiment, the DRDO spokesperson announced that the study's findings would be "confidential" until results were established, and a further official press release by the team stated that any inside analysis information may be disclosed only at the discretion of the principal investigator, DIPAS. Uninvolved doctors and other critics have questioned the validity of the studies and stated their belief that, although people can survive for days without food or water, it is not possible to survive for years, especially since glucose, a substrate critical to brain function, isn't provided. The veracity of Mataji's claims has also never been independently confirmed with all tests being indigenously conducted.