Graham Norton would be "fat as a fool" if he wasn't on TV.
The chat show host revealed that being on TV has made him conscious about his appearance, but if he didn't have to worry about the cameras capturing him in an unflattering light, he wouldn't care about his weight.
He explained: "I go to the gym. I don't enjoy it but you have to go. TV is a cruel mirror and if I wasn't on telly, I would be as fat as a fool by now. I'd be tucking my shirt into my trousers in the morning and looking at myself at a certain angle in the mirror.
"In my head, I would believe that's how I looked all day long. On TV, you see the people who are fat and all those unflattering angles make you want to stay trim."
The 49-year-old TV presenter is set to host a chat show marathon next month in honour of Comic Relief and has revealed the record breaking attempt - which will air from 7pm and run well past midnight - is going to be "epic".
He added to new! magazine: "We've got a lot of guests coming on the show, and if worst comes to worst, the guests can interview themselves if I collapse and nod off!
"I'll be having a glass of wine and maybe a bowl of grapes and some olives on the night, and hopefully I'll be fine."