Katy Perry bribes her tour crew for pizza.

The 'Dark Horse' hitmaker tries to eat healthily on the road but can't resist the lure of her favourite foods when she sees other people tucking in.

She said: ''At the beginning I brought someone out to make food that didn't have any dairy and very little gluten. But after a hundred shows I was like, 'Let's get pizza'.

''I try and keep it healthy on the road but the crew always have pizza around so I'm like, 'Give me a slice bro, I'll give you an extra hour's sleep if you give me a slice.' ''

The 30-year-old pop star finds her backstage rider ''boring'' because it only features healthy treats.

She said: ''We have healthy snacks. It's so boring. We have a lot of kale and a lot of dried fruits and probiotics.''

Katy credits her high energy levels in her performances to the fact she always makes sure she gets a lot of sleep, even though she doesn't keep conventional hours.

She told Britain's OK! magazine: ''I sleep a lot. That's where I get my strength and rejuvenation. My operating hours are very strange.

''I'm a nine-to-five girl but not in a Dolly Parton way - I'm a 9pm to 5am girl. I start my day about noon and end my day about 3am.

''I press snooze for about an hour [when I wake up] - I'm such a horrible snoozer.

''I usually do acupuncture or some kind of alignment and then I stretch and work out. I do my shower and my regimen, all my lotions and my potions.''