Singer Katy Perry, who tries to eat healthily on tour, says she cannot resist the lure of pizza when she sees others tucking in.

"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'," she said.

"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, reports femalefirst.co.uk.

"We have healthy snacks. It's so boring. We have a lot of kale and a lot of dried fruits and probiotics," she said.

The "Dark Horse" hitmaker credits her high energy levels in her performances to the fact she always makes sure she gets a lot of sleep though she doesn't keep conventional hours.

"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 9 p.m. to 5 a.m. girl.

"I start my day about noon and end my day about 3 a.m. I press snooze for about an hour (when I wake up) - I'm such a horrible snoozer," she told Britain's OK! magazine.

"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," Perry added.