07/10/2014 at 12:00 PM EDT
At his highest weight, Pawn Stars
's Corey Harrison tipped the scale at 402 lbs. But when his doctor put him on preventative diabetes medication back in 2010, the reality star says it was his wake-up call.
"I literally drove straight from the doctor to the lap band center and had the surgery almost immediately," Harrison tells PEOPLE of his 2010 weight loss procedure
. "Back then, the surgery was too expensive for my bank account, so I had to pay with four credit cards, but it was something I had to do – I was not going to get diabetes!"
After going through with the gastric band procedure, Harrison, 31, dropped 50 lbs. in the first six weeks post surgery, and lost another 100 within the first year. After starting his slim down, "I could never go back to weighing as much as I did," he says. "It made me realize what I ate, how I ate and what I did to myself. It was a WOW moment."
Now weighing in at 210 lbs., Harrison continues to have his band checked monthly, and leads a much different lifestyle.
"I'm actually excited to go to the gym now. I box 12 rounds a day five days a week," he says. "When I was a teenager I loved snowboarding, but in my 20s I was too big to strap my feet in the boards. Being able to finally touch my toes made me realize I could snowboard again, so I went out and got new gear immediately."
As he slowly continued shrinking over the past three years, Harrison has also inspired his fellow Pawn Stars
cast member and longtime friend Austin 'Chumlee' Russell
to drop some major weight as well.
"It was time for me to get healthy," says Russell. "I started at 320 lbs. and now I'm down to 225. When I first began, I eliminated all processed foods except mustard. Now, 'everything in moderation' is my motto."
The slimmer reality stars say fans of their show, which premieres its spinoff series, Pawnography
, tonight on History at 10 p.m. EST, have taken notice.
"When I meet fans, they are always congratulating me on the weight loss," says Harrison. "They actually say, 'You look just like that guy from Pawn Stars
, but you are a lot skinnier and better looking than him.' " I say, 'trust me, if I were going to pretend to be someone, it wouldn't be that guy from Pawn Stars