Kevin Thornton, 41, of Lithonia, Ga. lost 55 pounds

Current weight: 210 pounds

Pounds lost: 55 pounds

Height: 6 feet 1 inch

Age: 41

How long he's kept it off: Thornton started in August 2011. In April this year, he reached his current weight.

Personal life: "I received my Master's degree from Argosy University in industrial organizational psychology in April 2013," says Thornton, who is a certified life coach. "Evolutional Fitness and Life Coaching is my business. I'm following my passion and purpose of inspiring, educating and empowering others," he says. He's a cycling instructor at LA Fitness and leads a boot camp every Saturday morning. He's single and lives in Lithonia, Ga.

Turning point: "The turning point was when my brother came down to Atlanta for our family reunion and had a conversation with me about my weight gain and how I no longer put my health as a priority. [He said] that I was more concerned about eating hot wings and drinking beer," says Thornton. "That was a very truthful statement he made and it made me realize that I [had] to go back to putting my health first. That's when I started back to seriously training."

Diet plan: Breakfast is Greek yogurt with granola and fruit. Mid-morning he has a green smoothie with kale, mango, banana, celery, protein powder and almond milk. Lunch is a salad with salmon. Mid-afternoon he has a fruit smoothie with protein powder and dinner is grilled chicken, broccoli and quinoa.

Exercise routine: He does weight training five days per week, a spin class four days a week and high-intensity interval training, or HIIT, one day per week.

Biggest challenge: "The biggest challenge was the eating and drinking," he says. "I loved going to the sports bar to watch football and eat wings and drink beer. I eat fruit now when I get the munchies."

How life has changed: "(I have) more energy," he says. "I'm down to a size I have not worn since undergrad. I've used this journey to help walk into my purpose of inspiring and empowering others to help create a better you by life coaching and boot camps. I have dropped 50 pounds and now I have become a certified spin instructor and health coach to help others on their journey … I had to (make up my mind) that this is something I needed to do and I could not (accept any) excuses from myself to prevent me from doing it." For others wanting to lose weight, he recommends, "keep a journal of what you eat and what exercises you performed each day. Get a workout partner. Know yourself - if you are not the type to push yourself, then you may need to get a trainer or take class so you will be pushed to help you create a better you."