Big cheers for the 500-pound teen as his entire high school rallies to help him lose weight.

Fourteen-year-old Eric Ekis is one of the most popular kids in his school in Franklin, Indiana. But that's today. It wasn't always that way.

Depressed over the death of his dad, Eric turned to comfort food. A long hospital stay to recover from a broken leg added to his weight gain. By the time he started high school, he weighed more than 500 pounds. He was bullied relentlessly.

Eric told INSIDE EDITION, "I was basically a loner."

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Eric spent his early days of high school trying to be invisible. He walked the halls alone. He faced the daily humiliation of trying to squeeze his 6-foot 4-inch, 510 pound frame into the small desks.

Then one day, a teacher asked Eric whether he'd consider walking for exercise. It was the start of something big.

Word got around. Before Eric knew it, fellow students offered to walk with him.  More and more students came out to help him lose weight. They encouraged Eric to play basketball. He enrolled in a nutrition class to learn about healthy eating.

The kids even line up to encourage Eric before weigh-ins, which are still hard for him. It's a sight that moves his gym teacher to tears.

Teacher Lesleigh Groce said, "Being a mom, that's what you want for you kid, that's like the greatest thing ever!"

Eric's mother, Laura is overwhelmed by the outpouring of support, saying, "It's awesome! I love that he finally has friends."

Now, the boy who entered high school wanting to be invisible, is anything but.