U.S. actor John Goodman, who recently debuted a much trimmer physique, says he was nearly 400 pounds at his heaviest.

The 57-year-old former "Roseanne" star said on Wednesday's edition of "Late Show with David Letterman" that exercise was how he achieved his recent weight loss, UsMagazine.com reported.

Goodman did not, however, say how many pounds he has dropped. Some media reports have estimated he shed about 100 pounds.

"I'd lose 60 pounds every spring," the "Treme" cast member said, confiding his weakness is beer. "I got too fond of the corn and barley and just started missing it too much, and that screwed everything up. I just gained it all back and then some every year."

He went on to say he doesn't have a specific goal weight in mind, UsMagazine noted.

"I'm gonna base it on the fat content of my body. Whatever's healthy and right -- not go nuts," he explained.