Overweight or obese patients should be offered 12 months of weight-loss classes rather than the standard three months, according to research showing that the move could prevent tens of thousands of cases of obesity-related diseases over the next 25 years.

The study found that those given a year-long pass to weight-loss classes lost more weight and were better able to keep it off than those on three-month programmes or those going it alone with self-help guides.



While offering a year of classes would be more expensive than the typical three months, improvements to quality of life mean the switch would meet measures of cost-effectiveness set by the National Institute for Health and Care Excellence (Nice).

“One of the things we see with weight loss is that the more weight you lose, and the better you keep it off, the bigger the health benefits,” said Amy Ahern, first author of the study from the University of Cambridge.

Published in the Lancet by a team of researchers from institutions across the UK, the study involved 1,267 overweight or obese participants split randomly into three groups. Just over 200 of them were given self-help guides on how to lose weight and a short explanation by research staff. The remaining participants were split equally between those who were offered weight-loss classes for three months, and those offered them for 12 months.

The team followed up on the participants after three months, one year and two years. To reflect a “real world” scenario, participants were also allowed to use weight-loss techniques other than those offered to their group.

The results show that, on average, those offered self-help guides lost 3.26kg after a year, while those offered weight loss classes for three months or 12 months lost 4.75kg and 6.76kg respectively.



Those on the 12-month programme also had a greater drop in waist circumference measurements, fat mass, and markers of risk for diabetes, such as blood glucose levels, compared with both of the other groups.

After two years, participants in all groups had regained some weight, but those who had been offered 12 months of weight-loss classes still fared best, weighing on average 4.29kg less than at the start of the study.



The researchers then used a model to explore how much the different weight-loss classes would cost over a 25-year period.

The upshot was that offering three-months of weight loss classes would save about £2.68 per person over 25 years compared to offering self-help guides, as a result of savings from a drop in cases of weight-related diseases.

However, moving from offering a three-month to a 12-month weight-loss programme has a net cost of £49 per person, over a 25-year period.

But the researchers found that, compared to offering three-months of weight-loss classes, 12-month courses were estimated to result in 1,786 fewer cases of weight-related diseases – including hypertension, diabetes and heart disease – over 25 years per 100,000 individuals.

Despite the 12-month programme being more expensive than either three months of weight-loss classes or the use of self-help guides, researchers say the quality of life gained by individuals means that according to Nice benchmarks it would be considered to be cost effective to move to offering the longer course.

“It isn’t cost saving, but the benefits are considered to be worth the extra cost by Nice standards,” said Ahern.



But the team do not expect 12-month programmes to be rolled out any time soon, pointing out that local authorities are strapped for cash and that currently even provision of three months of dieting classes is patchy.

“Weight management services are typically commissioned by the local authority and you have got to consider that savings in the NHS in 25 years don’t necessarily resonate with the local authority now,” said Ahern.

While the study received co-operation and some funding from Weight Watchers, the authors say the company had no role in the research itself.

Naveed Sattar, a professor of metabolic medicine at the University of Glasgow who was not involved in the study, said the research builds on previous studies showing that commercial weight-loss programmes are more effective than those provided by the NHS.

“What, as a nation, we need to decide is can we fund that more widely and for longer to help people get a grip on their understanding of their diets and help them lose weight – and sustain that weight loss for a longer period of time and therefore retain better health?” he added.



The new study, he says, offers important evidence that “it should be possible and it is cost effective,” he said.