In November, he will begin basic training at Ft. Benning in Georgia, the news outlet reports. Roundtree eventually wants to become a police officer.
So how'd he go from 405 pounds to 205? Roundtree stuck to a strict 1,500 calorie-a-day diet and adopted an active lifestyle -- spending his time jogging, playing basketball, swimming and using home workout DVDs. When hand and foot injuries threatened to hinder his progress, Roundtree persevered, according to ABC 6.
"There's going to be days where you're like, 'Oh I don't want to do it', but you gotta keep doing it," Roundtree told the station.
As a child, Roundtree played football, baseball and basketball, but eventually picked up video games as a hobby and began to gain weight due to lack of exercise. He went on to play in gaming tournaments when he was in high school, according to theLancaster Eagle-Gazette.
Roundtree comes from a family of servicemen and women. His father, mother, and sister all served in the Army, according to the news outlet. But while he always had his sights set on serving himself, Roundtree found his poor health seemed to pose an insurmountable problem.
"I never would have imagined that he would do that," Roundtree's mother explained to ABC 6. "But when J. sets his mind to something, don't tell him he can't do it ... because he'll prove you wrong."