Khalid Davis once topped the scales at 370lb. The 35-year-old battled with knee, hip and ankle pain and was at a high risk of developing diabetes. Then 18 months ago he decided it was time to get serious about his health.

He has already dropped 120lb and is using his knowledge and experience to help others get in shape through Life Fitness BDA.

“People see me training and working hard and when I tell them I used to almost weigh 400lb they don’t believe me; they are shocked,” the personal trainer said.

“But Facebook has all the shameful pictures on it.

“That’s why a lot of people can relate to me. I’ve done something a lot of them have been struggling with on and off. They know I’ve been consistent with my diet and exercising and am not into the yo-yo-ing.

“I just want to be a healthier, happier person every day.”

Mr Davis’s wake-up call came in 2011. He was put on the scale at his doctor’s office — he hadn’t been on one in years.

“It was the kind of scale that only goes up to 350lb and it zinged past 350,” he said. “My doctor told me, ‘I don’t know how much exactly you weigh, but losing 200lb wouldn’t hurt’. He handed me some pamphlets about gastric bypass surgery and I learnt you had to lose a specific amount of weight before even having the procedure.

I told my doctor: ‘You can save these for someone else’. I’m pretty bullheaded. But I told him, ‘If you want me to do something I will go for it’.”

Mr Davis followed a low-calorie, liquid-based diet plan and dropped close to 100lb. But he was not entirely happy with the results. He had lost most of his muscle mass and was looking like a “gaunt noodle”.

The timing wasn’t the best either — he had just started studying for his certified public accountant exams and did not have much time to devote to healthy eating and exercise.

“Those exams are intense and all I wanted to do was work, study and sleep,” he said. “You don’t have a lot of time so you grab the fastest and most convenient thing possible.

“If you work where I did at KPMG that means going to L’Oriental Express or the gas station to grab a bite to eat. Plus, I was on one of those 800-calorie diets. With that you don’t really change your lifestyle or learn better behaviours.

“I followed it through, but it unravelled really quickly and I found I was putting on the weight faster than I was taking it off because I had lost all my muscle mass.”

He passed his CPA exams in December 2013; three months later he decided to change up his weight loss method.

Instead of trying an extreme diet, he spent weeks studying proper nutrition. In September 2014, he started putting everything he learnt into practice.

“I went to my best friend and said, ‘Instead of just sitting off and chilling, why don’t we work out together?’.

“So that’s what we did. We went to Bull’s Head and we were pushing my car up and down the parking lot and after that we went to National Stadium and would be hitting the steps.

“I was too heavy to run at that point. It would hurt too much. But the good thing was this time I was dropping weight, but building muscle at the same time. I was able to eat the normal calorie amount and still cut weight.”

People noticed. Requests poured in for weight-loss advice.

He didn’t feel qualified in giving it until last summer, after he had completed a course at the National Personal Training Institute in Orlando, Florida.

“I was about to go 35. I had a little heart-to-heart with myself and went online and saw the calendar at the school. They had just launched a 600-hour programme, which was their most intensive one ever.

“In two weeks I decided to go put in my notice with my job, bought a plane ticket and left.

“It was a five-month course and was taught by some of the best of the best. They focused on how we could train special populations — people who were obese, had arthritis, hypertension and Alzheimer’s, or women who were pregnant.”

He returned to the island in January and immediately launched Game Changer, a rapid weight-loss programme. Mr Davis set Bermuda Heroes Weekend in June as the time clients would see results. Thirty people signed up.

“People came in initially, looked at the meal plan and said, ‘This won’t be enough food for me’. But now they send me messages saying, ‘I can’t get all this food in’.

“I tell them, ‘Isn’t that an awesome problem to have? You went from chronically being hungry because you were eating too much of the wrong things, and now all of a sudden you can’t get through all the food you need to in a day. I like the ‘ahas’ more than I love to see the pounds dropping off.

“My clients think it’s weird when I weigh them in and don’t have much of an expression. To me it’s just weight.

“The real joy is in knowing they really get what they’re doing to their bodies and how things work. I have people come in with things like naggy knees and now their flexibility has increased and their knees aren’t hurting anymore. They start to get excited; it makes me feel great.

“I like when people are looking forward to our sessions and sending me links to different health videos they find online and when they tag me in pictures showing what they had for breakfast. I like pushing people outside their comfort zones and watching them do more than they ever thought possible.”

• Get in touch with Mr Davis at lifebda@gmail.com