Why 'Pawn Stars' Star Corey Harrison Lost 192 Pounds

— -- At 210 pounds, Corey Harrison is looking and feeling better than ever.

The "Pawn Stars" star, once nicknamed "Big Hoss," dropped nearly 200 pounds after learning that he was pre-diabetic three years ago.

"Literally, I'm driving home from the doctor's office kind of freaked out about it and I see the place where they do lap band [surgeries] and I just pulled in and said, 'What does it take to have the surgery?'" he told "Good Morning America." "I didn't have much money at the time. I pulled out four credit cards and put it on that and there you go!"

At the time, the History Channel star, now 31, weighed about 400 pounds. However, after having his surgery, he also changed his exercise and eating habits.

See 'Pawn Stars' Corey Harrison After 192-Pound Weight Loss

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"I can only have four to five ounces of food in my stomach," he noted. "When you only have that much space in there, you don't want to fill it up with crap."

Harrison also has a support system in his co-stars, including Austin "Chumlee" Russell. Inspired by Harrison's slim down, he began losing weight too, and is now down 100 pounds.

"Chum kind of thought we were gonna be fat guys together forever or something," joked Harrison. "I'm proud of him. He did it all with diet and exercise... [but] he's the sidekick! Let's not forget that."