NHS Wales: Under half stay with Champions for Health campaign
A campaign to encourage NHS Wales staff to lead healthier lives resulted in fewer than half of those who signed up sticking to the full programme.
More than 1,300 signed up to Champions for Health, with 456 "actively engaged" throughout the six-month pilot project.
Officials praised those who took part but Wales' chief medical officer said it showed the challenges involved in improving health across the nation.
The results will be analysed to see what lessons can be learned.
The project, inspired by the London 2012 Olympics, aimed to improve the health of NHS staff and their patients.
The staff who initially signed up for the campaign were asked to make two lifestyle changes and monitor their progress over six months.
NHS Wales said 302 people pledged to work towards a healthy weight, with 52 achieving their goal and "250 making progress towards a healthy BMI [body mass index]".
It said half of the 120 people who signed up to eat healthily ate five portions of fruit and vegetables a day for 52 days or more.
Lifestyle change options included drinking safely, taking regular exercise, healthy eating, stopping smoking and working towards a healthy weight.
Staff were encouraged to inspire patients and the public to lead healthier lifestyles.
One of the successful participants was Heather Evans, a maternity support worker at Llandrindod Wells War Memorial Hospital in Powys, who lost 2st (12.7kg) by exercising and eating healthily.
She said: "It has become a way of life now," adding that it had "transformed not just my lifestyle but that of my husband and three children too".
In a statement released by campaign organisers, London 2012 Olympics organiser Lord Coe said: "I would like to congratulate everyone who took part in Champions for Health.
"It's great that so many people were inspired by the games to challenge themselves to adopt more healthy lifestyles."
Dr Ruth Hussey, chief medical officer for Wales, praised the "fresh and innovative" campaign and said it was "fantastic that so many NHS staff from across Wales have crossed the Champions for Health finishing line".
But she added: "The campaign also underlines however, the challenge we face in Wales to engage people in health improvement.
"I am looking forward to seeing how we can develop Champions for Health further to help ensure we have a healthier and sustainable nation."
The campaign was led by the directors of public health in Wales and was supported by Public Health Wales and the 1000 Lives Plus programme.