Even as a child, nothing could overwhelm his obsession with food. His mother, who had lost her father as a teenager because he didn't take care of himself, tried to help Harmon eat less and be active. But neither her worrying nor his family history really reached Harmon.
And even though he was teased in school for being overweight, Harmon developed and hid behind a defense mechanism: being the "funny fat guy."
"When people laugh, it's fulfilling," Harmon said. "Filling that role enabled me to be a social chameleon and slide between friend groups."
Harmon remembered saying that with a childhood friend, who was also overweight. "I was just obsessed with food and consumed by it, and it didn't have limits," he said.
In middle school, Harmon would make a breaded chicken sandwich on white bread as an after-school snack each day. Getting his driver's license opened him to a world of fast food possibilities. By the time he graduated from high school, the 6-foot-3 Harmon weighed 285 pounds.
His college meal plan and student discounts at nearby restaurants provided convenient food around the clock. College is also where he started binge drinking every night. Even though Harmon's roommate would indulge with him, he was also an athlete who went to the gym every day. He often tried to coax Harmon into going with him, only to get a solid "no" each time. Harmon felt that he would be met with nothing but shame if he went to the gym.
"I thought people would laugh at me and look at me like I didn't belong there," he said.
But his insecurities, which had been mounting since middle school, grew stronger as he looked around at his friends, who were healthy and in good shape.
He attempted working out some at the gym but never committed for long.
By junior year, Harmon felt completely out of control and reached his peak weight of 315 pounds. Seeing the number "3" at the beginning gave the avid football fan a new perspective.
"I thought, 'this is what offensive linemen weigh, but I'm not an offensive lineman or an athlete,' " Harmon said. "The thing is, I never felt like I was 300 pounds, and no one ever looked at me and thought I was over 300 pounds, either."
He was spurred to start making small changes to his diet. He hired a personal trainer during the summer before his senior year and went to the gym twice a week. He dropped back to 285 pounds, but he was still eating unhealthily on the whole and stayed at that weight until graduating with a sociology degree in May 2013.
When Harmon temporarily moved back home that month, his parents revealed that they were getting a divorce. His father moved out the next day.
Harmon took a job in Lynchburg, Virginia, where he'd gone to college, and soon realized that it wasn't right for him.
In August, he was faced with the impact of the divorce combined with a breakup, the loss of a childhood friend to suicide, the loss of his second grandmother in the span of a year and the realization that his job had turned into a disaster. He entered a deep, dark depression. He would drink to excess at every opportunity and gained back some of the weight he had lost. He was consumed by pain and dreaded waking up each morning.
"It also brought all of these things I had buried -- the pain and insecurities of being overweight -- over the course of my life to the surface," Harmon said. "It scooped that stuff out and removed all of the boundaries."
Harmon finally wanted to make a change. He knew that he had to stop and help himself. And the career path he had envisioned when he was in college no longer seemed right. Fueling his passion for writing about football, Harmon started the Backyard Banter blog in December 2013.
"Writing about football saved my life," Harmon said. "I needed an outlet besides this job I had. When I started the blog, it was for fun. But it gave me confidence that I had never had before. People liked my writing and started responding on Twitter, telling me how good I was at it. And I thought, 'your life is worth living.' I decided to go for it and pursue football writing as my career."
That same month, he also committed to a total lifestyle change. Harmon put himself in therapy and saw a counselor. He realized that if his life was worth living, he needed to start with his health.
"If I want to feel better, I have to look in the mirror and be satisfied," Harmon thought.
Harmon started going to the gym six days a week, alternating cardio and weightlifting. He cut out carbohydrates and sugar, mainly eating eggs, lean meats and green vegetables. In eight weeks, his weight dropped into the 260s, and he watched his transformation in the mirror as muscles replaced fat.
Encouraged by the impact of the changes he had made, Harmon moved away from his strict diet and discovered a healthy balance that he could maintain. All the while, he was still losing weight, working toward his dream of being a football writer and even adopting a dog, Charlie, to keep him active with daily walks.
When NFL Media offered him a job and he moved to Los Angeles from Northern Virginia, Harmon weighed 231 pounds. But his first season as a football writer, and living in L.A., provided new temptations of free food and cut back on the amount of time he could spend at the gym. He gained back 10 pounds by the end of the season but didn't let the setback deter him from his lifestyle change.
In the offseason, he has maintained a six-day workout plan that incorporates running, weight training and yoga. Harmon is also back to a more strict diet including egg whites, kale, lean meats, fish, broccoli, Brussels sprouts and brown rice. He weighs 218 pounds, but that's not the end of the road for his journey to wellness.
"My goal is to never be satisfied," Harmon said. "Not with my health or career or anything else. I look and feel good, and I'm at an acceptable stopping point, but I always want to feel that there's always more I can do."
Harmon has a plan for his second season as a football writer and how to avoid inevitable temptations by thinking about how far he's come and the bigger picture. And by sharing his story, which quickly spread on social media, Harmon now feels accountable to his friends and family as well as his followers on Twitter and those who shared their own stories.
The positive reactions to his story also encourage Harmon to keep striving for more and he hopes to inspire people by sharing more in the future.
"I want to be an example and show that you can beat something like this and come out on the other end," Harmon said. "Change is possible. The things that I went through happened for a reason. I feel like I'm the luckiest idiot in the world. If the person I was could do it, you can, too."