Doctors and experts are baffled by an Indian man who claims not to have eaten or drunk anything for 70 years - but is still in perfect health.A team of scientists and doctors in Sterling Hospital, in the western Indian city of Ahmedabad, are studying the claims of Prahlad Jani, a local holy man, who is over 70 years old.He claims to have been blessed by a goddess when he was 8-years-old, which has enabled him to survive without sustenance and that he derives energy through meditation.Most people can live without food for several weeks, with the body drawing on its fat and protein stores. But the average human can survive for only three to four days without water.Al Jazeera's Imran Khan reports.