At 28 years old, Mike Giannulis was 493 pounds and so obese that he missed out on things others might take for granted, like kissing a girl or even experiencing a first date.

The only time he would step foot outside the house was to visit nearby family.

"I don't have a full-length mirror anywhere in the whole entire house, and if I can just avoid seeing myself … out of sight out of mind," Giannulis said. "I mean, who would want to see this? I just feel like no girl deserves this."

Giannulis' brother, Mark, feared for his life. "I really think he can't get up off the couch sometimes because of his weight," he said.

That's when Chris Powell and " Extreme Makeover: Weight Loss Edition" entered his life and set a goal for Giannulis to lose half his body weight - 246 pounds - in the next year.

Powell was with Giannulis through the tough workouts and at the 90-day mark, he lost a staggering 129 pounds. By the six-month mark, Giannulis was a brand new man with a new lady in his life.

"I've got a brand new girlfriend and things are going awesome," Giannulis said.

Giannulis had lost so much weight that he was not only off the couch but was able to compete in a triathlon, a feat that would have been impossible just a few months before.

"I know how hard Michael has worked at this triathlon. You don't find many people like him," said Giannulis' girlfriend, Meghan. "I love him so much. I'm just so proud of everything he's done."

At the final weigh-in, 12 months after Powell came into Giannulis' life, he weighed 238 pounds, down more than half his original weight.

"In all the 29 years I have lived," Giannulis said, "this has been the best year of my life."

After the show concluded, however, he found himself giving into temptations and slipping back into old habits. Refusing to let that happen, Giannulis made a drastic move: He left his home in Tarpon Springs, Fla., to move closer to Powell in Phoenix, Ariz.

"He caught himself," Powell said. "He realized that he what he was doing, especially after he lost his purpose, he fell back into some of his old patterns and some of those triggers he was experiencing. Those social triggers. They were feeding the addiction again. So he picked up from Florida and moved and he's actually living down the street from me now."

Powell also believes it's important to realize one is never on the weight-loss journey alone.

"You have to realize that no man is an island," he said. "You can't do it alone. As we go through this process, real life happens, and we need to talk about it. We need to share in order to heal. It's really important to reach out to those different people or there are incredible online sites as well."

Powell recommends one key tip for maintaining weight loss.

"We all create what we call a 'smart goal.' It's specific, it's measurable, it's attainable, realistic and time-sensitive," he said. "And it's so important that we live with that purpose, that we're always reaching toward that goal."