Def Leppard guitarist Phil Collen has confirmed the band's next studio outing will be an album rather than an EP.

The change of plans comes after an incredibly successful songwriting session at frontman Joe Elliott's studio in Ireland – and the experience was fuelled by a vegan diet.

Collen reports: "I just got back from a very productive and creative Def Leppard session in Dublin. We got about 15 songs started. What we thought was going to be an EP has now definitely turned into an album of new Def Leppard material.

"The whole time we were there, the incredible gourmet chef Jeni Cook put the band on a raw vegan food diet – no, it's not just lettuce. We were treated to some of the tastiest foods I've ever had in my entire life.

"We had raw vegan desserts every day, along with sushi, pizza, Mexican-style wraps and incredible salads. The coolest side effect was that I lost seven pounds, while keeping all of my energy and strength up."

He reveals the band were so impressed by the skills of Cook – wife of Paul, drummer with the Sex Pistols and Collen's side project Manraze – that they'll continue the vegan them on their US tour with Kiss.

Def Lep's 10th studio album, the follow-up to 2008's Songs From The Sparkle Lounge, is expected next year.