A fast-food lover who once weighed 560 pounds has completed a half marathon after doctors gave him the ultimatum of “diet or die.”

Darren McClintock ran the race Sunday in Newcastle, England, as his latest feat in his year-long health journey, which has seen him lose more than half his body weight, Teesside Live reported.

“If you’d told me I would be doing the Great North Run, even a month ago, I would have laughed!” he told the outlet.

The 28-year-old from Pallister Park said he got serious about his health last October when doctors warned him that his life was at risk.

He enlisted the help of friend and personal trainer, Mike Hind, who tacked up signs urging restaurants not to serve McClintock fast food, according to Teesside Live.

Since the dire warning from doctors, McClintock has started exercising and shed more than 260 pounds.

He saw his hard work pay off Sunday when he crossed the finish line along with 57,000 other runners at the Great North Run.

“It’s an amazing feeling afterward, knowing you have done it,” McClintock told Teeside Live. “I found it hard but the sense of achievement is unbelievable.”