In the final episode of Celebrity Operation Transformation on RTÉ One on Wednesday night it was revealed that the five leaders have lost almost seven stone in four weeks.
Elaine Crowley has lost 1st 8lbs, with Brenda Donohue losing 1st 1lb and Katherine Lynch shedding 13.5lbs.
Gerald Kean has lost 1st 11lbs and Karl Spain has lost 1st 6.5lbs.
"I feel so much better - that's the key thing," said comedian Spain, who is now under 18st for the first time in a decade.
Solicitor Kean has become a non-smoker and has reduced the insulin intake for his Type 2 diabetes by 90 percent.
"I saw this as a wonderful opportunity to help me live a healthier, longer life," he said at the end of the show. "It's like everything I did before I did it to win or I did it to help people. This is the first thing I felt I was doing for myself."
RTÉ presenter Donohue, who has seen her body fat drop by five percent, described the series as "a surprise gift". "It's like something you'd like to buy for yourself but you wouldn't," she explained. "To give something of yourself - I think that's what being a leader is all about."
Fellow leader Lynch is now in the top 25 percent of women her age for aerobic fitness. The comic and singer said the show was one of the best things she had done in her life. "I hope I can do it without the camera looking at me because I can do anything when a camera is looking at me," she added.
TV3 presenter Crowley had the biggest inch loss of any of the leaders - 8.5 inches off her waistline. "At some point you have to stop trying and you have to start doing," she concluded.
"Operation Transformation for me is the doing part. People may laugh and say it's a weight-loss show but it actual does make a real difference. It actually translates into real differences in real people's lives."
To follow the leaders' food and exercise plans, visit: ot.rte.ie.
