And last night, the gruelling workout regimes and diet plans paid off when contestant John Rhode triumphed on the show, weighing in at a svelte 220lbs (15.7stone).
The 41-year-old teacher from Arizona won the title of the Biggest Loser and the $250,000 prize after shedding 50.56 per cent of his original body weight.
Rhode attributed his success on the show to his huge motivation to lose the weight. I would have to say that it was my desire,' he told Ann Curry on The Today Show this morning.
'I had a sincere desire to make this change. but I wanted it to be a true change. I want to keep the weight off. Losing the weight wasn't so difficult. Keeping the weight off, that will be the true test.
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Rhode last night beat fellow competitors, NFL player Antone Davis and tattoo artist Ramon Medeiros to the big prizeI still don't know how I did it, but I'm grateful,' the season 12 winner told People after the live televised final. 'Anything is possible. I've been given a new life. Now I just want to keep working hard, stay focused and help people.'
Rhode said he planned to celebrate his win by 'giving my wife a big hug and a kiss and holding on tight to my boys.'
And he plans to treat himself with his prize money but not go too crazy.
'I am going to try and be responsible with the prize money,' he told Digital Spy. 'My wife would like a car - we're not going to get a new car, but we'll get a new to her car - and we'll pay some debt and put some money away for a rainy day. I'm definitely ready to spoil my wife, but responsible spoiling!'
And Rhode's fellow contestants were forewarned of his determination to win the crown, when he informed them he wouldn't be 'happy until (he was) pulling confetti out of (his) hair' at the final.
The show's trainers were also impressed by Rhode's dedication to the performance.
'I knew John was going to win the very first day he came on the Ranch,' Bob Harper said after the show.
Anna Kournikova added: 'John was very vocal, focused and straight to the point.'
The theme of this season was 'Battle of the Ages' with the contestants separated into three groups, under 30, 31-49 and the over 50s.
Age is just a number,' Rhode told People after his efforts at home and on the contestants' ranch. 'I made the most of every moment on the ranch because I knew (my wife) was at home struggling like a single parent, and with our two boys - and our youngest is autistic,' he said in a direct message to his wife.
'Baby, I didn't waste a single minute on the ranch. The sacrifices I made on the ranch will never compare to what you did for me, making it so I could be there. I will owe you a debt of gratitude forever, and I thank you from the bottom of my heart.'
He told Curry today that he is already making plans to workout and keep the weight off.'It is very much a psychological, emotional battle. My plan right now is I'm focused on running the LA marathon. After that, then I'm going to have to find a new focus,' he said.
'Right now my next goal after the LA marathon is a goal of just maintaining my size. I'm wearing pants that are 34/32 and I'm comfortable in them, I like them. If the pants start to become snug, maybe I've got to rework some things. But right now, I don't want to be a slave to the scale anymore'
'I have comfortable clothes, I enjoy the clothes. If that becomes an issue, then I know I'm doing something I need to fix.'
