The Dancing with a Stranger singer has been opening up about his lifelong struggle with weight issues and body image, revealing he underwent liposuction surgery at the age of 12.

In a frank interview with I Weight ambassador and actress Jameela Jamil, the 26-year-old explained that after having been "chubby" as a kid and too self-conscious to swim, he then developed "breasts" in his adolescence, which began to negatively impact on his mental health.

His mum took him for the operation, which he admits worked at first but ultimately "didn't really change anything" because he soon put the weight back on.

"When I was a kid [at five or six] I was chubby and then it would get worse and worse and worse and I was holding a lot of weight in my chest," said Sam. "And then when I hit 11-years-old I went to the doctors.

"I was so self-conscious that it was affecting my mood everyday and my life as a teenager."

Referring to the surgery, he said:

Quote Message: At the time I think I was very happy about it, [but] it didn't really change anything. I think I put the weight back on in two weeks as I hadn't really figured out my relationship with food.

At the time I think I was very happy about it, [but] it didn't really change anything. I think I put the weight back on in two weeks as I hadn't really figured out my relationship with food.

Quote Message: The basis of all my teasing, all my bullying my whole life - was my chest.

The basis of all my teasing, all my bullying my whole life - was my chest.

Sam also revealed that he once considered having a sex change and that he yearns to be free from the trappings of fame.

"If I had the chance to do this all again," he confessed, "I would not do this... I wouldn't."

In an accompanying message to the Instagram video post, Sam wrote: "I know this sounds dramatic but this interview completely changed my life.

"Being able to talk so openly about my body issues and feeling so safe whilst doing it was truly liberating."