Dr Michael Mosley says men are more “deluded” than women when it comes to their own weight and fitness.
The doctor and broadcaster is fronting a new Channel 4 series to help people who have piled on the pounds in lockdown.
Dr Mosley told the Press Association: “An awful lot of people are unaware of how much weight they put on, particularly around the gut.”
Research shows that only 10 per cent of people who are obese know they are but that the figure is only 7 per cent for men, Dr Mosley said, while “women are more aware of it”.
He added: “I think men are deluded – they’re much more prone to thinking they are leaner and fitter than they are.
“They take less care of their health and yet they are at greater risk of things like diabetes. So, I think men are just a little bit more deluded.”
Dr Mosley said those taking part in his Channel 4 show had “no idea how much weight they put on” and “the worst of the fat is the stuff you get around the gut”.
He said: “I got people to guess … how big they thought their tummies would be and then bravely they allowed me to measure it or they measured it themselves.
“They were out by between two and 12 inches.”
He denied his new Channel 4 show, which offers practical advice to overhaul viewers’ lifestyles, was about fat shaming.
“Body shaming is awful. It is incredibly ineffective. Telling people they’re fat never, ever works,” the presenter said.
“None of this is about fat shaming. It is entirely about helping people who are obese and who want to do something about it.
“Any diet is only ever going to work if the person wants to do it.
“This is a health show. What I’m trying to do is make these people healthier and put them on a healthier path. So, this is not about weight itself so much as about health.”
Lose A Stone In 21 Days With Michael Mosley airs at 9pm on Wednesday on Channel 4.