At the age of 12, David Benavidez weighed 18st 6lb (117kg).

When the American steps into the ring on Saturday against Briton Anthony Yarde as the defending WBC light-heavyweight champion, he will be 12st 7lb (79kg).

Now 28 and a two-weight world champion, images on social media of Benavidez as an overweight 13-year-old training with his father show just how far he has come to get into the shape necessary to reach the top.

"At the time, I would have never imagined I would be a top fighter and one of the biggest in boxing today," he told BBC Sport.

"I always had faith in myself. I always knew that with hard work, anything is possible. I've never given up on myself. I started off and I wasn't in shape.

"I did have the will and the dedication to get to where I wanted to go. That's the message I want to give to the kids.

"Other kids and other men could look at my story and take it into their life and achieve anything."

As his older brother Jose thrived in the amateur ranks, plans were put in place for Benavidez to drop 100lb.

By the time he was 15 he was sparring with pros such as multiple middleweight world champion Gennady Golovkin.

"I had been boxing since I was three, with my dad training me," recalled the Phoenix-born fighter.

"I really believed in myself. When I got back into boxing aged 11, we started moving little by little and cutting the weight.

"When I lost that first 100lb, I was at 260lb and I got down to 168lb. That's when I knew I got the biggest part out of the way, and now let's continue to train and see where it takes us.

"I wasn't thinking about being a world champion, I just worked hard every single day. This is not a sprint. I like to think of it as a marathon."

In a sport full egos, America's 30-0 world champion is as humble as they come on a journey to inspire the next generation.

It wasn't until Benavidez got to 17-0, with 16 knockouts, that he started to believe he could be the best in his field.

Coming from a place where six-packs and muscles are expected, he has talked openly about the weight challenges he faced as a youngster and draws "motivation" from inspiring others.

"I get a lot of people who message me online and tell me my story has been an inspiration and that it's helped them drop weight," added Benavidez.

"Some people need to see it's possible for them to put it in their lives.

"Going through everything I went through makes me really happy that people can see my story and put it in their lives. I keep telling my story over and over again because there's always going to be someone in my position.

"I don't mind talking about it because I know how it feels to think you won't ever lose weight or get to where you want to get in life.

"For people to see that and get to where they want makes me really happy."

After two fights as WBC interim light-heavyweight champion, Benavidez was upgraded to full world champion status before his fight in Saudi Arabia against Londoner Yarde.

At super-middleweight he twice lost his world title because of troubles out of the ring, once for testing positive for cocaine in 2018 and another for missing weight in 2020.

With those issues behind him, Benavidez is eyeing a future fight with light-heavyweight king Dmitry Bivol if he can overcome the 34-year-old Yarde, who was previously stopped in 2019 by Sergey Kovalev for the WBO light heavyweight belt and by Artur Beterbiev for the WBC, IBF and WBO titles in 2023.

"I haven't overlooked Anthony Yarde, though," he added.

"I know it's his third time at a world title. I know he's working extremely hard. I know he has a lot of power, I know he has guts and a big heart.

"I want all the titles and Dmitry Bivol has all those belts. There are also other great fighters like Artur Beterbiev.

"There's also the opportunity to go up to cruiserweight and fight [Gilberto] Zurdo Ramirez.

"There are a lot of great fights for me, but first things first, I have to go and take care of Anthony Yarde and then the sky's the limit."