Robbie Williams is a "night owl" and doesn't go to bed until 6am.
The 'Let Me Entertain You' hitmaker - who has children Teddy, seven, Charlie, five, Coco, 20 months, and Beau, four months, with wife Ayda Field - "doesn't like" the hours he keeps but he finds he gets his best work done in the early hours of the morning.
And Robbie's unusual routine means he now only eats one meal a day.
He said: "I don't get up in the morning. You know people say I have been fasting, well, no.
"I have just been sleeping through that fast. I don't sleep until 5am or 6am. I'm a night owl, it is the way I am programmed. I don't like it.
"I don't want to be but I am very productive from 1am until 5am. I get a lot done and I wake up at noon. Then I will have a meal at 5pm and I will feel full."
The 46-year-old star tries to follow a healthy diet most of the week because he finds sugar makes him feel depressed and sluggish, but he enjoys at least one cheat day.
He told talkSPORT's Andy Goldstein: "I live saintly all week. We have 'f**k it Friday' here. Last week I had McDonald's fries with ketchup and mayo.
"I do get a sugar hangover. When I put sugar in my system I am a bit depressed and a lot slower than I usually am as sugar is poison. I don't have sugar six days a week, it inflames.
"You do get in the slipstream of it and it does become normal. The last four days I have one meal a day. Just dinner."