The Stay With Me singer changed his diet and managed to shed more than 42 pounds (three stone) since shooting to fame, but Sam admits he faces a daily battle to stay away from the food he loves.

He also feels under pressure to change the way he looks now he is in the public eye, and fears male stars are under the same obligation as their female counterparts to stay thin.

"I still feel pressured to look a certain way," Sam tells Britain's NME magazine. "For women, the pressure in this industry is horrendous and it's got to stop. But it's the same for guys, even though they won't speak about it."

However, Sam hopes speaking out about his problems will help other male pop stars, adding, "I want to be a voice for that: just because I've lost weight doesn't mean that I'm happy and content with my body. Because of the media, and because of what I feel I should look like, it's always going to be a battle in my head."

The singer recently revealed he had to undergo two sittings for sculptors at Madame Tussauds because he lost so much weight after they started creating his waxwork.

"It took me three to four hours, I had loads of dots on my face and had to stand still in that (the figure's) position," he told the Press Association. "And then I lost like three stone after I did the sitting so they had to do another one and then shave off the wax, which is a good problem to have."

Sam's statue was unveiled at the Madame Tussauds attraction in San Francisco, California in August (15).