Reports suggesting that Julian Assange’s two-year confinement inside the Ecuadorian Embassy in London has brought on dangerous, even life-threatening health problems may or may not be exaggerated.

Mr Assange himself told reporters today that his health had suffered, but was not specific, saying that his environment – in which he does not have access to outside areas – was a difficult one even for a healthy person to live in for so long.

Being starved of sunlight and fresh air certainly has some direct impact on our bodies. Up to 90 per cent of the vitamin D we acquire comes from the sun. However, Mr Assange is fair-skinned, and just by standing next to a window with his sleeves rolled up should have been sufficient to maintain healthy vitamin D levels, which can also be topped up by eating oily fish.

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However, the psychological impact of spending so long indoors, cut off from friends, family and the ordinary rhythms of daily life, could be more serious.

Simon Griffin, professor of general practice at Cambridge University said that, if he were Mr Asssange’s doctor, the state of his mental health would be his first concern.

Video: Assange to leave the Ecuadorian Embassy

“If someone’s been incarcerated, even with the benefits of Skype and so on, they might have lacked company and contact with close friends and relatives,” he told The Independent. “There are also advantages to your mental health from going outside, seeing green space.”

Conditions such as depression, anxiety and stress, all of which might be brought on by incarceration, could also have an impact on the metabolism, Professor Griffin said.

To fend off the risks of a sedentary lifestyle, Mr Assange is understood to have had access to a treadmill, but it is likely that his activity levels have been low. Another risk might be his diet.

“If he could get his 30 to 60 minutes moderate to vigorous physical activity a day that would maintain his metabolic state – that doesn’t mean he doesn’t have long periods being sedentary,” said Professor Griffin. “There’s some suggestion that, even if have spells of physical activity, if you have long uninterrupted spells of sitting and lying that can have adverse consequences, if you’re stuck indoors in front of a television you tend to snack, tend to eat foods not prepared fresh. That means higher salt, higher fat, higher refined carbohydrates in your diet.