Moody was born to Young Sun as the youngest of three children, raised in the Dallas, Texas area. His father left the family early, leaving him to be raised by his mother and his grandmother, Han Soon Chang. And Moody's uncle began helping him practice and train for football after seeing how well he performed in pee wee football. Physically a late bloomer, coaches initially hesitated to put him in the running back role that he desired. When his family moved to the suburb of Coppell, Texas, Coppell High School already had a highly regarded senior running back, one of the best in school history, and asked the sophomore Moody to spend a season at wide receiver. After insistence by himself and his uncle, Moody was allowed to play running back at the junior varsity level. During that time, Moody grew taller and put on 25 pounds. His junior season saw him rise to the varsity team where he finished the season with 1,319 yards and 12 touchdowns. His abilities attracted interest from a number of prominent college football programs, notably Texas, Miami and Southern California. Moody originally verbally committed to Texas, but USC linebacker coach Ken Norton was able to eventually persuade Moody to change his commitment to the Trojans, enticing him to the challenge of competing against a number of other talented running backs.
Moody started his college career at the University of Southern California in Los Angeles. As a true freshman, Moody was the second leading rusher in the 2006 season, gaining 560 yards on 79 carries in a rotating platoon of running backs. He was named the Pacific-10 Conference Freshman of the Year in 2006. In the summer before the 2007 season, he was featured as one of three USC running backs on the regional cover of Sports Illustrated's college football preview edition. The Trojans entered their 2007 fall training camp with a high number of scholarship running backs, all of which were highly touted recruits; in August, midway through camp, Moody announced he was transferring from USC. Looking to be a featured player, Moody stated he had "felt forgotten" coming into training camp because of an ankle injury that forced him to sit out the Trojans' last four games of the 2006 season and a hamstring injury that caused him to sit out nearly all of spring practice; he then bruised his knee at a mid-camp scrimmage and had to sit out further. After looking at several schools, including Oklahoma State and North Carolina, Moody transferred to the University of Florida.
University of Florida (2007–2010)
As required by NCAA transfer rules, Moody was forced to sit out the 2007 season with the Florida Gators; but was permitted to practice with the scout team. Welcomed by a team that needed a power running back to relieve quarterback Tim Tebow, Moody had some difficulties adapting to the spread offense used by the Gators. He had 58 carries for 437 yards in the 2009 season and 66 carries for 521 yards in 2010. Moody participated in the Gator Pro Day but was not drafted in the 2011 NFL Draft.
Professional career
Buffalo Bills
On April 30, 2011 Moody signed with the Buffalo Bills. He was released on October 21. In 2013 Moody signed in Europe with the Dresden Monarchs in the German Football League. Playing three games and rushing 11 times for 156 yards and one touchdown. In 2014 Moody signed with the Vienna Vikings in Austrian Football League. In seven games Moody had 722 yards in 71 rushing attempts and scored six touchdowns. He also had nine receptions for 118 yards.