The Real-Life Diet of Superman Star Edi Gathegi, Who Got in Hero Shape With Progressive Overload

When Edi Gathegi landed the role of Mister Terrific in Superman, he knew that playing the character would require a tremendous amount of physicality. But when he met with James Gunn to discuss the part, a member of the Justice Gang who’s skilled in martial arts and a genius inventor, the director assured Gathegi that he could look any way he wanted. Even upon receiving that news, the 46-year-old actor decided to commit to being in shape.

Gathegi, who also played Laurent in the Twilight series and Darwin in X-Men: First Class, is no stranger to canonical roles in fictional universes. He’s also been around the block enough to know exactly what he needs to do to prepare his body for a physical part. For Superman, he underwent a body recomposition (with the help of a personal trainer, Paolo Mascitti, who also helped him count macros) and aimed to eat around 3,200 calories a day. Now, with the movie premiering on Friday, Gathegi tells GQ about working out side-by-side with the Man of Steel, why he avoided just bulking up for the role, and more.

GQ: What is this that you’re drinking, by the way?

Edi Gathegi: This is an iced Americano. Two shots, water, and ice. I just got off milk a week ago because we are entering the shredding phase. My trainer, we get into arguments about it because when I don’t do milk, I can tell. He’s like, “This is in your head. There’s not that many calories in milk. There’s not that much fat in milk. You can continue the milk if you want to.” I notice the difference. I’m in tune with my vessel.

What’s the difference? How do you feel when you’ve been drinking a lot of milk?

What it comes down to is, I am inadvertently doing a caloric deficit. Cutting the milk out, I’m just not getting the 120 calories that it provides me within the day. So, I do feel the difference, but I don’t think it really has too much to do with the milk, per se, versus the amount of calories.

You mentioned a shredding phase. Were there other phases for Superman?

Yeah, this has been a year’s journey. After we booked the job, we all had to wait—I don’t know, was it, eight months—because of the strikes. We shot it for five months, then it’s been in post-production for 11 months. It’s mind blowing.

I think because my character is a lesser known character, there was a lot of leeway for our own interpretation. James [Gunn] told me, “Listen, you can do whatever you want. If you want to be chubby, you can be chubby. You can do whatever you want with this, and we’re going to create the character for the general audiences together.” Now, I had to consider wire work, stunts, just the physical toll that playing a part like this would play on my body. Also, as we get older, our muscles start to atrophy. I felt like it was an opportunity to just keep my body strong. I knew that I wanted to commit fully. I felt like the character rewired my level of investment.

I asked for a personal trainer, and they gave me one of the best guys in the business. He was also training Superman [David Corenswet]. He takes each client and assesses them individually. There’s no cookie cutter approach to his method. What does your body need? How does your body perform? Let’s cater a workout to that. In my situation, we wanted to do body recomposition. We didn’t want to bulk up, because we didn’t know how much time that we would have to shred. We just turned all of the fat on my body into muscle. His philosophy is: a good trainer is a boring trainer. Progressive overload is what he calls it. You either have to do one more rep—or a couple more reps—or you have to add a little bit more weight for each set. You’re constantly building. It got to the point where I just couldn’t even believe the amount of weight that I was pushing. It just felt absurd. I would look at weight sometimes and go, That’s not for me. What are you doing? It was for me, and I didn’t realize that I had gotten stronger!

You’ve played superheroes before, you’ve played a vampire, you’ve played a cowboy. Are you more drawn to these roles where there’s a physical element to them?

I am a physical actor. I think that’s always been something that I’ve gravitated towards in my work. Even if it’s not physical, I try to find the physicality. I like using my body. I wasn’t really big into sports, but I played sports when I was younger. It’s funny, I was just thinking about this the other day. When I got into grad school I was so muscular, and my teachers talked about tension and transformation, and they encouraged me to stop working out. So, throughout my entire training, I wasn’t working out. Then when I graduated, I kept that mentality. It wasn’t until I got Twilight where I became conscious of my body again. X-Men took it to the next level. I also haven’t thought about it much since X-Men. I work out, I keep it together. But it wasn’t until this movie where I went back to what I did when I was in my twenties.