Mark Jansen
Mark Jansen lost 100 pounds prior to his “Big Brother” stint. CBS

Mark Jansen is an inspiration for everyone trying to shed extra pounds.

According to E! News, Mark went through a massive transformation before he appeared on CBS’ reality show “Big Brother.” The personal trainer was overweight, and in his own words, he was a “big boy.”

Reddit shared a before-and-after photo of Mark and its’s obvious how massive the transformation was for the Season 19 reality star.

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A number of fans commented on the photo and many were impressed at how Mark was able to maintain his gentleness after being bullied due to his weight. “Agreed. :( I really hurt for him when he talked about being bullied. It speaks to his character that he's such a sweet soul after facing that,” one user commented. “I almost cried during that part. I feel his pain,” reads another comment.

Prior to the show, Mark admitted that he used to be bigger. “I played football for a year at University Buffalo and I graduated. I was a big boy,” he told “Big Brother” alum Jeff Schroeder. “I weighed about 330-340 and then I knew I had to get in shape.”

“I always wanted to be in the fitness industry and I knew I had to lose some weight. So I started losing weight, I lost over 100 pounds and got into body building and then people started asking me how I did it. So I started helping people and I just fell in love,” Mark continued.

Aside from his weight, Mark has gone through a lot of challenges in life. He lost his dad when he was young and was raised by a single mom. When he was 17, his mom died. If he wins “Big Brother” he plans to start a foundation that would help single moms and children with deceased parents, Reality TV World reports.

Mark is a bodybuilder. He studied abroad and went to an NFL regional combine. As for his favorite hobbies, he loves lifting weights, hiking, watching movies and relaxing on a beach.

How do you find Mark’s weight loss transformation? Drop a comment below.