David Blaine

As David Blaine prepared to celebrate reaching Sunday’s halfway point of his planned 44-day ordeal living in a small Perpex box suspended beside Tower Bridge, questions were growing over whether he is really starving himself.

“Why hasn’t Blaine got any thinner?” screamed the Sun newspaper. It said he still had “a flabby chest and love handles”. The tabloid suggested that the American illusionist had been taking “high-protein liquid food” through the tube delivering water to him.

In an attempt to confirm its theory, the paper spoke to an onlooker. “He doesn’t look like he’s lost weight at all,” it quoted office worker Justine Booker, 32, as saying. “In fact, he looks porky.”

The claims were strenuously denied by Blaine’s spokesman, and by Sky, the television station providing 24-hour-a-day coverage of the stunt. “He is just getting water,” they said. So what is the truth? Is he cheating, or isn’t he? Is his “starvation diet” just an illusion?

Armed with binoculars and some scepticism, The Sunday Telegraph on Saturday took a leading nutritionist to observe Blaine and deliver his professional opinion on whether the magician looked like someone who was on day 21 of self-inflicted starvation. Professor Thomas Sanders, the director of the Nutrition, Food and Health Research Centre at Kings College, London, joined the flocks of onlookers on the south bank of the Thames at Tower Bridge.

Through binoculars he scrutinised the man swaying 40ft above him. “It is quite possible for someone to survive without food for this length of time with no glaringly obvious physical changes,” the professor said. “The early symptoms of deficiency are psychiatric and we have no way of assessing his mental state from the ground.”

Perhaps because of the intrusiveness of the Sun, Blaine was hiding his so-called “love handles” underneath a loose white T-shirt and baggy tracksuit bottoms. But there could be an innocent explanation for his not appearing emaciated. “One would expect him to have lost in the region of eight or nine kilograms over a period of three weeks of not eating anything,” said Sanders. “But he doesn’t move around much so it may be less.”

The nutritionist did not rule out some form of cheating, however. “There is absolutely no way that Blaine can protect himself against serious mineral and vitamin deficiencies over such a time. I hope for his sake that he is being given a supplement. If not, he risks long-term problems and even death. But if he is taking a supplement then this isn’t a fast, a starvation diet, an illusion or whatever else you want to call it. It’s a sham and a fake.”

Sanders said any supplement in Blaine’s water would be easily detectable by taste.

There was only one way to tell for sure. We walked over to below the box and shouted up to Blaine, telling him we wanted to carry out a test. “You wanna check my water?” he shouted. “Get ready. Here it comes...” and he poured water from a bottle.

We caught enough for Sanders to taste. He raised the cup to his lips, took a sip, smiled and said: “Well I never. It is just plain old H2O. Very filtered and tasting flat but it certainly doesn’t contain additives.

“But that doesn’t prove anything. They could add something for just a few minutes every day or two. Or he could have some pills up there in his box... or a corner of his bedding soaked in minerals, especially salt.”

All the Sun’s photographers need now is a picture of Blaine sucking on a corner of his blanket, and the proof will be there.