In theSeason 4premiere spoilers ahead!
we learn some news about Baby Jack and, inthe second episode, we see how Toby andKateare managing.
Meanwhile, an obviously thinner Toby says that he’s losing weight from all of thestress.

And, to be honest, we had the same reaction.
“Toby looking good,” one fantweeted.
But those episodes didn’t mark Chris Sullivan’s first time transforming the character on the show.

Here’s how the actor became Toby.
How can that be?
It wasn’t a tricky camera angle or CGI that made Sullivan look thinner.

Rather, he wasn’t wearing a prosthetic costume aka a"fat suit."
Yes, for most of the show, Sullivan has worn prosthetics to make Toby appear heavier.
Take a moment to let that sink in.

“The fact that [Toby]wears a fat suitis sooooooo disappointing,” one fantweeted.
“Like they couldn’t find an actual overweight white male actor?”
a fan mused onTwitter.

With the secret out, one fanclaimedthat the show would never be the same.
However, he made sure to explain that the prosthetics are necessary.
“He was the best man for the job,” Metz dished.

Sullivan’s costar added that actors “wear prosthetics all the time.”
She continued, “This just happens to be weight as opposed to a nose or the chin.”
Toby’s weight may be part of his story, but it’s certainly not hiswholestory.

In Season 3, audiences learned that the usually happy-go-lucky Toby actually struggles withdepression.
I’ve certainly gone through my fair share of anxiety and depression."
It’s all part of the same process."

Yet, they’re also alike on a deeper level.
Instead, it was the thoughtfulness of both the character and the actor portraying him.
Sullivan himself told the publication, “Our personalities are pretty close.”

Some stars have downrighthated working together, but that’s not the case with Chris Sullivan and Chrissy Metz.
They have a great working relationship, according to Sullivan.
This Is Usis a scripted drama so, of course, the actors have a plan to follow.

However, Sullivan revealed in an interview withTVLinejust how his dramatic scenes with Metz play out.
Perhaps that’s what makes these two so perfect onscreen.
And some of the things Toby goes through onThis Is Usare quite heavy.
When asked a similar question during an AOLBuildforum (viaMSN), Sullivan gave more insight into his process.
“While I’m shooting [scenes] I try not to [decompress].
He also revealed that he practices yoga and meditation as a way to get out of the dark headspace.
Just as the Pearsons are a close-knit family, so, too, are the actors who play them.
They’re so close that Sullivan said guest stars could feel unwelcome.
It’s really terrifying,” he explained to theChicago Tribune.