Coulthard started in F1 as a test driver for Williams in 1993

At nearly 6ft (183cm) tall, Coulthard is taller than most F1 drivers and felt he had to resort to extreme measures to keep his weight down for racing.

"I stopped eating fattening food and, before I knew what had happened, I was bulimic," he said.

"In my mind the only way to keep my weight down was making myself vomit."

The 36-year-old, who now weighs 11st 6lb (72.5kg), said his weight dropped as low as 9st (57kg).

"I have always taken racing seriously, even when I started out in karting," he added.

"By my teens, however, my focus - in particular, my weight - took a slightly more sinister turn. I was nearly the same height as now but I weighed only just over nine stone.

"At first I was just very, very lean. I became skin and bone, but I weighed myself every morning, noon and night - in the evening if I was half a pound heavier, I'd get in the pool and swim."

Coulthard, who will extend his F1 career into a 14th full season with Red Bull in 2008, made the revelations in his autobiography.

The Scot admitted that his behaviour could be viewed as obsessive, but said it drove him to achieve success.