A specialist doctor from Auckland Medical School says the puffy appearance of the castaway survivor found in the Marshall Islands last week is consistent with a chronic physiological insult.
Jose Salvador Alvarenga is recovering in Majuro following 13 months at sea after being blown off course during a fishing trip off southern Mexico.
The Associate Professor of Anaesthesiology at the University of Auckland says maintaining hydration in a small boat with no water supply is a huge challenge and this would be the thing mostly likely to result in death.
Simon Mitchell says Mr Alvarenga's paradoxically bloated appearance is consistent with a state of long term starvation.
"You can get in to a situation where your liver's not producing enough protein in your blood stream and that can cause fluid to leak out of the blood stream into the tissues so it gives you this puffy appearance. He has had a prolonged, chronic metabolic insult which has resulted in a derangement in a number of his physiological functions and here he is looking a bit puffy."
Associate Professor Mitchell says if people are resourceful and can cope mentally, survival under the most extraordinary circumstances is possible.