(CNN)Two years ago, Michael Watson was in a rut. The 6-foot-4 inch teen weighed 335 pounds and was often bullied about his weight.
Ohio teen loses more than 100 pounds while walking to school every day
"My self-confidence was zero," Watson, who turns 18 on Wednesday, told CNN.
As a junior at his Canton, Ohio, school, the teen decided to make a commitment to walk to and from school every day, about 20 minutes each way. And he made some changes in his diet.
When he walks across the stage at graduation later this month, the McKinley High senior will be 115 pounds lighter.
One low moment came when a classmate told Watson he had something on his chin. When Watson rubbed his chin, the boy told him, "'No, third one down,'" Watson said. "That really hurt."
Moments like that fueled his walking.
Even if Watson wanted to take a day off, he couldn't. "I didn't even know when the bus came," he said.
And on days when it was raining, people would ask if he wanted a ride. Michael declined. In addition to the walking, the student made a commitment to dieting, which especially took discipline when he was working his after-school job at a fast-food restaurant.
The boy who was too afraid to approach girls now says he's surging with confidence. After the weight loss, he has no problem asking one out.
Terrance Jones, who works as a family specialist and graduation coach at the school, told CNN that Watson's story stuck with him.
"It's an example of courageous personal development that's rare for a high school student," Jones said. "Mike's decision to the initiative to live a healthier lifestyle and to stay consistent with it will always stay with me."
Jones said Michael's story was the catalyst for him to create a "McKinley Senior Limelight" on Facebook to showcase students' stories.
Michael is in his school's vocational culinary arts program. He plans to take a full-time job after graduation, and after being inspired by a drama course he took last year, plans to pursue a dream of being an actor.
He said over the past two years he wasn't always perfect when it came to dieting, but if he lapsed, he told himself "Every day is a new day." And over time he saw significant results.
"Anybody can do it if they put their mind to it," he said.