Crispin Butler, senior coroner for Buckinghamshire, said Mosley’s death was “most likely attributable either to heatstroke (accidental) or [a] non-identified pathological cause”.
The hearing was told Mosley had been staying with friends and family when they travelled to Pedi Beach in Symi, which is part of the Dodecanese island chain.
Butler said: “Michael had intentionally left his mobile phone back at the house to prevent it getting wet on the ferry.
“Later in the afternoon, Michael decided he was going to walk back home rather than take the ferry.
“He had his rucksack, one litre of water and a biscuit, and had a hat and umbrella. Michael was described as looking energetic and cheerful as he set off.”
He said: “Ultimately Michael’s death was classified as indeterminate, which we would describe as ‘unascertainable’...
“No medical cause of death could be ascertained, meaning Michael’s death may have been due to a medical event or as a result of a non-traumatic accident.”
Mosley is credited with popularising intermittent fasting through his book The Fast Diet.
In July, his widow Dr Clare Bailey Mosley spoke of her “overwhelming” grief following his death.
The BBC honoured the doctor-turned-science broadcaster with a day dedicated to him, during which presenters and audiences were encouraged to do “just one thing” to improve their wellbeing.
He presented various science programmes and films including the BBC series Trust Me, I’m A Doctor, which looked at healthcare in Britain, and hosted the BBC Radio 4 podcast Just One Thing.
In a 2015 programme, he made two black puddings out of his blood to showcase its nutritional value.
