Richard Gadd Gained 100 Lbs. for His New Filming — Here’s the Shocking Reason Why

The Baby Reindeer star trained for over a year — sometimes twice a day — to look completely different for his new HBO role. Richard Gadd has shared one of the most dramatic physical transformations in recent television history. The 36-year-old star of Baby Reindeer revealed that he gained nearly 100 lbs. before filming began on the HBO series Half Man.

Gadd opened up about the journey during his appearance on the April 29 episode of the How to Fail podcast, hosted by Elizabeth Day. He explained that moving on from his character Donny Dunn in Baby Reindeer required far more than a mindset shift — it had to show up in his body too.

“I knew in order for people to buy me as Ruben I needed to get away from Donny Dunn in almost every single way I could,” he said during the interview.

When he was filming Baby Reindeer, Gadd weighed just 151 lbs. (68.8 kg). He had intentionally kept himself thin and lean to feel vulnerable and youthful in the role. But before filming Half Man, he pushed his weight all the way up to 242 lbs. (110 kg) at his heaviest — a swing of over 90 lbs. between the two projects.

“So a huge, huge difference,” he said on the podcast.

Speaking to Men’s Health magazine, Gadd revealed that his preparation started well over a year before filming. He trained six days a week — sometimes even twice a day — while keeping a close eye on everything he ate.

“I had a nutritionist. I had a personal trainer. There was a company in England that would send meals up — it was always high protein, no matter what,” he told the magazine.

He gave full credit to his trainer David Jenkins and nutritionist Dr. Andrew Usher for keeping him disciplined throughout the process. “Together they put me through my paces,” he said. “They never let me slack off and always pushed me, and I’m always up for a challenge.”

Gadd also made clear that he wanted the weight gain to look natural and real on screen — not like a gym transformation. “A lean bulk wasn’t going to give me what I needed to look big. And I also wanted Ruben to look real. I never wanted it to be a veiny, steroid look,” he told Men’s Health.

The changes went beyond just the scale. Before filming started, Gadd also reworked his voice, beard, and hairstyle — doing everything possible so audiences would not see traces of Donny Dunn when watching him play Ruben.

“I needed to change everything,” he said. “My size, my voice, my beard, my hairstyle, everything. I needed to transform.”

What made the challenge even bigger was that Gadd was not just acting in Half Man — he also created and wrote the British miniseries. So the intense physical preparation was happening at the same time as all of his other responsibilities behind the camera.

“It’s hard enough if just your job as a sole actor on something is to kind of transform,” he said. “But doing everything else alongside is obviously a huge commitment.”

Baby Reindeer — the Emmy-winning Netflix series that made Gadd a global name — is currently streaming now. His new project, Half Man, is available to watch on HBO Max.