“I puke quite a lot before going on stage,” says the 23-year-old. “Though never actually on stage.”
The pre-gig puke, she says, is down to stage fright. But it guarantees a great performance from the Brit and Grammy-winning superstar.
“The bigger the freak-out, the more I enjoy the show,” she confirms, laughing.
No airs and graces for Adele, she tells it like it is. And seemingly no subject is out of bounds for the young Londoner – not even the failed relationship that inspired the songs on her record- breaking second album, 21.
The story goes that after the release of Adele’s 2008 debut, 19, things started to go wrong for her and her then partner.
The pair split up in April that year, but it wasn’t until December that she felt ready to pour her heart out and reveal everything on record.
“I just had to wait and be ready to be honest with myself, and to properly articulate what I wanted to say. Otherwise it would have been 19, Volume 2,” says the singer. “I needed that light bulb to come on.”
From there, it was a fairly quick writing process, which involved super-producer Paul Epworth – “I wouldn’t be able to cope if I had as many ideas in my head as him, I’d explode,” says Adele – former Semisonic frontman Dan Wilson and OneRepublic’s Ryan Tedder, a respected tunesmith who has written hits for female superstars like Beyonce, Jennifer Hudson and Whitney Houston.
“I first met Ryan in a lift in the States with about 100 balloons,” she explains. “He said he knew it was me because he recognised my laugh – Scott Mills had made a clip of it on his Radio 1 show, which he’d heard while in the UK.
“Anyway, he came in the lift, popped loads of the balloons and said we had to work together.”
That 21 was a success is an understatement. By far and away 2011’s top seller worldwide, the album has taken little more than seven months since release to break the ten million mark and looks likely to reach 13 million sales by the end of the year.
Earlier this week, it was announced that the chart-topping album is to be recognised for a hat-trick of achievements by Guinness World Records.
Adele has set new UK records for a solo female with both the most consecutive weeks at number one (11, beating a record previously held by Madonna’s The Immaculate Collection) and the most cumulative weeks at the top (18, erasing out both Alanis Morissette and Shania Twain, who shared the previous record at 11 weeks).
In addition, she’s the first woman to have two singles and two albums in the UK top five at the same time, which only The Beatles had achieved before in 1963.
Not bad for a singer who admitted in her first interview with The Guide – shortly after the release of her debut album in 2008 – that she didn’t know what would happen if her music career didn’t take off because she hadn’t had a proper job yet.
From a non-musical family, Adele says she knew she wanted to be a pop star from a very early age.
“It all comes from impersonating the Spice Girls and Gabrielle,” she explains.
“I did little concerts in my room for my mum and her friends. My mum’s quite arty – she’d get all these lamps and shine them up to make one big spotlight. They’d all sit on the bed.”
Later, when her dad’s best friend, a dance producer, rightly declared Adele’s voice “wicked”, he invited her to record a cover of Heart Of Glass.
The first time she got a microphone in her hand, at the tender age of 14, she realised that music was indeed her calling.
She signed up to the Brit School, the Selhurst college which counts Leona Lewis, Kate Nash and the late Amy Winehouse among its former students, and it wasn’t long after graduating before record labels started to notice her obvious talent.
Even so, when XL Recordings called her in for a meeting, Adele was nervous enough to take a pal along with her to the audition.
“I never, ever thought I’d get signed,” she says. “The A&R guy e-mailed me and I was ignoring it. I didn’t realise they did all these amazing names.”
The rest, as they say, is history.
Adele’s unique singing voice has rightly propelled her to stardom on both sides of the Atlantic, and her honest attitude to fame is refreshing.
“I’m such a blagger,” says the singer modestly. “I think I’ve blagged most of my career so far.”
Adele, Usher Hall, Lothian Road, Saturday, 7pm, £29.50, 0131-228 1155