Colson Smith still "battles" with his weight and will do for the rest of his life.
Colson Smith spoke to Runner's World (c) Ben Knight
The 'Coronation Street' star has shed several stone in the last few years after finding a passion in running, but he thinks he will struggle with his image forever.
He said: "That fat kid is the kid that I've looked at every day in the mirror and I still see him now.
"It's a battle I'm probably going to carry with me for the rest of my life.
"You don't shrug off that kind of thing so easily.
"But I'm not going to take a big pay cheque to hold up a pair of my old trousers. I want to tell the story my way."
The 23-year-old star - who plays Craig Tinker in the ITV soap - admitted nearly all of the comments written about him online are to do with his appearance.
He said: "You do get people saying: 'Oh my god, you were amazing in Corrie tonight,' but I'm less likely to acknowledge that than the ones saying: 'You are literally the worst actor I've ever seen.'
"The comments are mostly about my appearance. I'd say pretty much 99.9 per cent of anything that's written about me, I do see."
When Colson first started running he would only do so in the pitch black to ensure he wouldn't be seen by anyone, but he has since grown in confidence.
Speaking to Runner's World UK - https://www.runnersworld.com/uk/ - he added: "My first runs were in the witching hour, pitch black, I had a snood and a cap on.
"I did not want to be seen.
"But then you see other people who look like you, who are in the same position as you, and the inhibitions start to run off.
"Running does give you confidence. You're not doing it for anyone else, and no one else is going to do it for you.
"Once you have that idea in your head, you're on to a winner."
Read the full Colson Smith interview in the November issue of Runner's World UK, on sale from today.