Anyone who's ever dieted knows how hard it is to shave off a stone, so imagine trying to lose a third of your body weight. Far beyond a few tweaks here and there, it involves a complete transformation of the way you eat and live.
Wil Graham, 2011 winner of TV diet show The Biggest Loser UK, did exactly that. The 30-year-old shrank from 24 stone 7lb to 16st in just 13 weeks to win the series and scoop a cash pot. And thanks to the passion for running he found as part of The Biggest Loser, Wil's dropped another four stone since the show ended in December.
We caught up with the weight-loss champion to discover his tips for slimming down and staying svelte.
You shed a whopping eight and a half stone on ITV's The Biggest Loser. What was the biggest change you made to your diet?
The main lesson for me was portion control. It wasn't that I always made the wrong food choices - though I did slip up occasionally - it was the fact that I was over-fuelling. I was eating the equivalent of a small family's worth of calories every day. From a nutritional perspective I learnt that little and often is the best approach, rather than overeating or starving yourself.
And what did you learn about exercise?
I learnt that I enjoy it! I used to exercise a lot as a teenager, but I stopped as I got older and started working. As it happened gradually, I never fully appreciated how much my fitness levels had disappeared. Now exercise is now a way of life for me and I feel lethargic and lazy if I don't do it. I also find it really clears my head and it's a 'me' time treat- there's nothing nicer than putting my headphones in and going for a run.
When did you start running?
I started running on the show. They first got us to walk on the treadmill and then they set us a one kilometre running route. At first we could only walk the first 500m, then we'd slowly jog back. Towards the end of the show I could briskly jog around the route a few times. After the show finished in December, I kept up my running and carried on improving.
How often do you run now?
I run a minimum of five times a week and I try to go out in the morning. There's a good two-mile circuit where I live, so I try to lap that a few times. You can wake up in a bad mood and feel tired, but as soon as you've been for a run you feel ready to take on the day.
What tips would you give to people taking up running who want to lose weight?
I'd recommend people go at their own pace when they first start. It can be tempting to push yourself, but you need to listen to your body. If you go too far one day, it might mean you're in too much pain to complete your run the next. Set yourself realistic targets and try to gradually extend your distance or speed each week. And make sure you've got a good iPod playlist - that always helps.
Do you run now to keep the weight off or to chase down PBs?
I did the Reading Half-Marathon at quite short notice and without training properly. I wasn't in the best shapes but I got a decent enough time, about 2:20. At first I was proud to have run a half-marathon but afterwards I realised that I could have run it a lot faster. I run to stay in shape but I've become quite competitive with myself. That's partly why I'm looking to running the Royal Parks Foundation Half-Marathon in October with UNICEF, as I want to try and smash my time.
What are your aims for the Royal Parks Half-Marathon?
I'm aiming to run sub-2:00 - anytime between 1:50-1:55. Other than that my focus is to earn as much money as I can for UNICEF. They are a fantastic charity and they improve the lives of so many children across the world. It will be great to support all the hard work they do.
Did you hit a weight-loss plateau? If so, how did you overcome it?
It's really tricky to keep losing weight. I was very naïve when I first left the television show. I was close to my target weight, so I relaxed and started eating whatever I wanted to again. I soon realised you can't return to your old habits and you need to keep putting the work in. You can either continue dieting and become a little obsessed with food or focus more on exercise. I've found setting myself sporting challenges works best for me. I train so I can compete in a race, rather than constantly fretting about weight-loss. I ran the Fisherman's Friend Strongman Run in Germany in April [the largest obstacle race in the world]. It was definitely tough on the day but the training helped me to control my weight.
What advice would you give to people who are nervous about staring to run?
I always used to have excuses and thought I was too busy or tired to exercise after work. However, you're not doing yourself any favours. Be selfish and go the gym or take the time to make your lunch the night before you go to work. Do what's going to help you in the long run or you'll just end up feeling guilty.
Have you got any healthy snacks you would recommend?
I've got a very sweet tooth and as I'm Scottish, I find it hard to resist tablet [a traditional Scottish fudge-like sweet]. In the past I tried to deny myself treats and hoped to eat as little as possible. Now my relationship with food has changed - if I have a craving for something sweet, I'll just eat it. If I don't, I know I'll be thinking about it for days and I'll end up bingeing on a whole bar, rather than just having a few squares. I tally up the calories, then I run it off in my next session.
This October Wil will run the Royal Parks Foundation Half-Marathon for UNICEF. Wil Graham is pledging to raise £550 for UNICEF's life saving work to ensure that no child, no matter where they live has to struggle without adequate food, shelter or an education. To run the Royal Parks Foundation Half-Marathon with Team UNICEF, register here: www.unicef.org.uk/halfmarathon