Credit: Don Arnold/; Kevin Mazur/

Not-so plus-size anymore!

Jonah Hill looked skinnier than ever at the ESPY Awards in L.A. on Wednesday night.

The once-rotund Superbad star, 27, has been slimming down for months in preparation for his role in action flick 21 Jump Street (based on the Johnny Depp 80s TV hit). The Daily Mail estimates that the 5' 7' star has lost about 40 pounds.

Back in the spring, a pal told Us Weekly that Hill "went on a diet for the movie, but gained weight at first! Finally, he got a nutritionist and a trainer." He first debuted a slimmer look at a March event -- but his ESPYs night physique, four months later, looks even more dramatic.

"It's not fun," Hill told the Los Angeles Times of his get-fit plan. "I wouldn't say it's the most fun endeavor I've ever took on in my life — but it's important. And I'm enjoying it. If I eat something unhealthy now, I kind of feel a little weird and my body hurts."

Tell Us: Did Hill lose too much weight?