The truth hit Ryan Benson when he couldn’t fit into a seat on his son’s favorite roller coaster: He’d regained the weight he’d fought so hard to lose as a contestant on “The Biggest Loser.”

In 2005, Benson was crowned the first winner of the popular TV show, which ran for 12 years and has since ballooned into a multi-million-dollar franchise. Benson lost 122 pounds and won $250,000, but he’s since returned to his pre-show weight.

That problem wasn’t unique to Benson — a 2016 study from the National Institutes of Health (NIH) followed more than a dozen former “Biggest Losers” and  found that of the 14 people studied, 13 regained a significant portion of the weight they lost on the show. Four were heavier in 2016 than they were before they set foot on the set.

Experts have various takes on why this happened, blaming everything from inevitable biological factors to the show’s shaming approach to weight loss. But the show’s producer, JD Roth, argues that anyone can push themselves to slim down by breaking what he calls “bad behaviors.”