Singer Sam Smith has posted a shirtless photo of himself on Instagram, as a way to "reclaim" his body.

While these kinds of posts aren't an unusual for celebrities on social media, Smith used this moment to open up about his battle with body image, admitting to starving himself for weeks ahead of upcoming photo shoots.

"Some may take this as narcissistic and showing off," he wrote in his Instagram post, which features some bad language so obviously ask your mum before you click.

"But if you knew how much courage it took to do this and the body trauma I have experienced as a kid you wouldn't think those things."

With nearly a million likes, his fans have praised him for "inspiring" them with his "beautiful" message.

In a 2016 survey of more than 1,000 boys aged between eight and 18, 55% said they would consider changing their diet to look better and 23% said they believed there was "a perfect male body to strive for".

The survey also found that the four biggest sources of pressure on secondary school boys to look good were:

Friends (68%)

Social media (57%)

Advertising (53%)

Celebrities (49%)

Despite the relentless pressure that young men can feel from the media, the survey found that more than half of the boys (56%) would find it difficult to talk to a teacher about their confidence and nearly one-third (29%) would find it difficult talking to their parents about it.

Here are eight other male celebrities who have spoken out about body image and are calling on the media to change their attitudes.

1. Antony Costa

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In 2017, Blue singer Antony Costa appeared on Lorraine and opened up about the "fat-shaming" he had experienced on social media.

Costa explained that when he first started out in show business before the dawn of social media, receiving criticisms "was water off a duck's back" but now, the public are quick to point out flaws in selfies and paparazzi photos which he believes can be harmful.

"Me as a bloke in the business, it's hard because you've got to keep up with the joneses, to be seen to have the six pack," he said.

"But I'd rather be me and have a good personality then have a six pack".

2. Chris Pratt

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Yes, you read that right! Actor Chris Pratt - who plays the gun-toting, butt-kicking, ripped Star-Lord in Guardians of the Galaxy - has struggled with body image, too.

In a press conference for the film in 2014, he said: "I'm sure I can't relate to what females go through in Hollywood. I'm sure I can't.

"But, I do know what it feels like to eat emotionally, and… to be sad and make yourself happy with food.

"And then to be almost immediately sad again and now ashamed and then to try to hide those feelings with more food. I know what that's like. It's a vicious cycle and it's a very real thing."

3. James Corden

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In an interview with Rolling Stone in 2016, talk show host James Corden opened up about how he dealt with his confidence in school.

He explained: "If you're big at school, you've really got two choices. You're going to be a target. If you go to school and you're me, you go, 'Right, I'm just going to make myself a bigger target. My confidence, it will terrify them.' That's how I felt in school."

Corden also touched on his frustrations on the way Hollywood represents larger people.

He said: "I could never understand when I watch romantic comedies. The notion that for some reason unattractive or heavy people don't fall in love.

"If they do, it's in some odd, kooky, roundabout way - and it's not. It's exactly the same."

4. Wentworth Miller

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Prison Break actor Wentworth Miller opened up about his depression after being the subject of an internet meme joke by The Lad Bible in 2016.

Miller wrote in a Facebook post: "In 2010, at the lowest point in my adult life, I was looking everywhere for relief/comfort/distraction. And I turned to food."

He continued: "It could have been anything. Drugs. Alcohol. Sex. But eating became the one thing I could look forward to. Count on to get me through".

5. Alex Sharp

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Alex Sharp starred alongside Lily Collins in Netflix drama To The Bone, which follows a girl's treatment for anorexia.

When Collins' character is admitted into a recovery home with six other patients, she meets Luke (played by Sharp), the only male patient in the house.

Talking to Broadway World about portraying a man struggling with an eating disorder, Sharp said: "It happens a lot and I think sometimes - because it is under-discussed and a taboo subject generally - when it is discussed it tends to be more about the female experience, because it is more prevalent, numerically.

"There had never been a representation of that in a feature-length movie. So that was something I was very interested in doing."

6. Ashley Hamilton

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Iron Man 3 star Ashley Hamilton told People in 2013 that he had suffered from bulimia and anorexia since he was a teenager and that he used drugs and alcohol to control his food addiction.

"I've been free from bulimia for years but I still struggle with food, restricting or overeating. That's been the hardest for me in sobriety," he admitted.

He continued: "It's almost like drug addiction is totally acceptable to talk about in Hollywood. But food addiction? Nobody wants to talk about that. It's really shameful as a man to have that."

7. Ed Sheeran

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The chart-topping singer told Planet Radio in a 2014 interview: "I was never really happy with my image and then I realised it was because I was eating fried food and drinking beer every day. You don't have to kill yourself by getting into shape. Just eat right and don't drink every day."

Commenting on body image pressures in the music industry, Sheeran said: "There's enough fat people in the industry and there's enough skinny people in the industry and there's enough ginger people in the industry.

"There's enough of everyone in the industry, and usually the ones that aren't attractive are the ones that do the best."

8. Matt McGorry

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Before starring in Orange is the new Black and How to Get Away With Murder, Matt McGorry used to be a personal trainer and competitive bodybuilder, which actually made him more critical of his body.

When asked what we could do to change the conversation around male body issues he told US TV show Today: "When we lock our boys away from these feelings, not only are they more likely to hurt themselves but they're also more likely to hurt others and to be the ones who are policing masculinity amongst other men."

9. Robert Pattinson

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Despite being nominated as one of the world's "sexiest men alive" in 2009, Twilight star Robert Pattinson has still admitted to feeling insecure.

In an interview with Australia's Sunday Style magazine in 2013, the Twilight actor revealed he suffers from body dysmorphia - an anxiety disorder that causes a person to have a distorted view of how they look.

"I don't have a six-pack and I hate going to the gym. I've been like that my whole life. I never want to take my shirt off," he said.

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