In case you hadn't already noticed, Zach appeared at a screening of Birdman over the weekend looking quite slim.
He told Conan O'Brien that he credited his weight loss with quitting drinking last year.
He also got married and had a baby in the past few years so he's probably just living a happy, healthy life.
So if you ask him a dumb question about his lighter figure...
...you can expect this kind of response.
Now let's all agree to stop asking people about their weight on red carpets. Great!