Gaunt Steve Jobs explains himself

After months in which computer king Steve Jobs has looked more and more gaunt with every public appearance, Apple's CEO has quashed concerns that he is quitting as head of the company - or indeed about to die - with a letter on the company website. It is intended to explain why tomorrow's keynote speech at Apple's annual Macworld expo in San Francisco is being given by the company's marketing boss Phillip Schiller and not the great man himself.

Jobs wrote: "As many of you know, I have been losing weight throughout 2008. The reason has been a mystery to me and my doctors. A few weeks ago, I decided that getting to the root cause of this and reversing it needed to become my number one priority. Fortunately, after further testing, my doctors think they have found the cause - a hormone imbalance that has been 'robbing' me of the proteins my body needs to be healthy."

In all likelihood, this hormonal imbalance is related to the 'Whipple' procedure, an operation to remove part of his pancreas that Jobs underwent in 2004 after he was diagnosed with a rare curable form of pancreatic cancer. The pancreas is the organ which ensures that humans digest the right amount of nutrients, and Jobs, who was once a fruitarian and is now a vegan, must struggle to eat enough protein in his daily diet.

So, when he manages to balance his hormones, Jobs - and his trademark black turtleneck - should soon be back at the helm. Apple need him. Such is Jobs's personality cult that after he released his explanation on Monday, the company's shares leapt by almost four per cent in morning trading. ·