Is Zac Efron on a diet?

Something we never, ever thought we’d be discussing. Is Zac Efron on a diet?

The sexy actor recently bulked up for a movie role. Zac has said he gained about 18 pounds to play an Iraq War veteran in The Lucky One.

“I was just eating, eating, eating,” he told E! News.

Well now that filming is over, is Zac trying to slim down? On Thursday the 23-year-old actor was spotted at an L.A. studio with a bag of grub from Z.E.N. (Zero Effort Nutrition) foods, a diet delivery service that helps stars eat calorie-controlled meals.

Ex girlfriend Vanessa Hudgens is actually a big fan.

“I’m so thankful there’s a service like Z.E.N. Foods that tastes GREAT and makes it so easy to eat right,” she says on their website.