The Australian Idol judge, who's been named as the new spokesman for Jenny Craig, tells Phillip Koch why he's determined to ditch his blubber.

Australian Idol judge Ian "Dicko" Dickson has been a harsh critic of overweight wannabe pop stars, so it came as a nasty shock when a doctor labelled him obese and told him to lose weight or die young.

"He did the calculations and warned that I need to lose 10 to 15 kilograms," admits Dicko.

"The doctor said I was technically obese — and I found that really confronting. I'd never considered myself obese."

Like a lot of men, Dicko, 46, had slowly put on weight but tended to suck in his belly when he looked in the mirror each morning — and failed to see what his wife Melanie and daughters Esme, 18, and Edie, 16, were complaining about.

He had, without realising it, become a "podgy" middle-aged man — and after some soul searching, a 104kg Dicko called weight-loss giant Jenny Craig.

"I started on the program two weeks ago," confirms Dicko, who is this week unveiled as the face of Jen4Men, the company's program designed for overweight men.

The realisation he wasn't a snake-hipped young rock 'n' roller any more was a bit of a shock, but Dicko was far more concerned about the serious effects of obesity on his health and life expectancy.

"I'm not doing this because people are pointing their finger at 'fat Dicko'," insists the music mogul, who also co-hosts the Vega 91.5FM Melbourne breakfast show with comedian Dave O'Neil and Big Brother runner-up Chrissie Swan.

"I'm doing this because I had a serious medical wake-up call, and that was being called obese. You don't want to be known as obese – technically, morbidly or comedically.

"Then I had the aftershock of being told that if I stayed this weight, it would rob me of five years of my life..."