The actor, who has previously spoken about his battle with depression, made the confession on Facebook.com in response to an Internet meme he spotted circulating on social media about his weight gain.

A picture of Wentworth with a ripped physique from Prison Break, which ran from 2005 to 2009, was compared to another image of him looking noticeably larger, with a paunch visible under his red T-shirt. Alongside the pictures, a message reads, "When you break out of prison and find out about MCDonald's monopoly".

Wentworth told fans the overweight picture was taken when he was "at the lowest point in my adult life" and he turned to food to help cope with depression and suicidal feelings in 2010.

"I've struggled with depression since childhood. It's a battle that's cost me time, opportunities, relationships, and a thousand sleepless nights," he writes. "I was looking everywhere for relief/comfort/distraction. And I turned to food. 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.

"There were stretches when the highlight of my week was a favorite meal and a new episode of TOP CHEF... Sometimes that was enough. Had to be... And I put on weight. Big f--king deal."

He admitted seeing the overweight picture, which reminds him of his dark days, as a meme on social media made "it hurt to breathe" until he gave it meaning.

"And the meaning I assign to this/my image is Strength. Healing. Forgiveness... Of myself and others... If you or someone you know is struggling, help is available. Reach out. Text. Send an email. Pick up the phone. Someone cares. They're waiting to hear from you. Much love."

The 43-year-old, who came out as gay in 2013, previously told the audience of the 2013 Human Rights Campaign Dinner that he first tried to commit suicide as he struggled with his sexuality aged 15.