Commercial weight-loss programs such as Weight Watchers and Slimming World are more effective and cheaper than family doctor-based services led by specially trained staff, according to the findings of a study published on Friday.
With a global epidemic of obesity putting huge pressure on health budgets, researchers at Britain's Birmingham University wanted to compare the effectiveness of doctor-led weight loss programs against several well-known commercial schemes.
The results suggest that while commercial schemes generally help people to lose weight, doctor-led programs do not.
After 12 weeks, people in all the schemes studied had achieved significant weight loss, but the average loss ranged from the highest at 9.7 pounds with Weight Watchers down to three pounds on a program led by primary care staff.
A control group who were not put on any specific diet program but were given vouchers for free access to a gym for 12 weeks lost just as much weight on average as those using health clinic-based based weight-loss programs.
After a year, statistically significant weight loss was recorded in all groups apart from the primary care programs, but Weight Watchers was the only program to achieve significantly greater weight loss than the control group.
Kate Jolly, a clinical senior lecturer in public health and epidemiology at Birmingham who led the research, said primary care-based weight loss services led by specially trained staff are "ineffective" while commercially provided services "are more effective and cheaper".
Worldwide, around 1.5 billion adults are overweight and another 0.5 billion are obese, with 170 million children classified as overweight or obese. Obesity takes up between two to six percent of healthcare costs in many countries.
This latest research, published in the British Medical Journal (BMJ), comes in the wake of the first gold-standard randomized controlled trial of Weight Watchers last month, which showed that the program works far better than getting doctors to tell patients to lose weight.
Another study in the United States published in 2003 found that one year's free access to Weight Watchers resulted in an average weight reduction of 7.7 pounds after one year.
In the BMJ study, which involved 740 obese and overweight men and women in Britain, several other commercial weight loss program were also studied including Slimming World, Rosemary Conley and a group-based dietetics program as well as general practice one to one counseling and pharmacy-led one to one counseling.
Weight Watchers and Slimming World are both group-based weight-loss schemes where people trying to shed pounds are given dieting tips and encouraged to go to weekly meetings to be weighed and discuss their progress with other members.
At a cost of roughly $64 for 12 weeks, they are also relatively inexpensive, particularly when compared to the the billions of dollars spent on healthcare for overweight and obese people worldwide every year.
In a commentary on the BMJ study, nutrition experts Helen Truby and Maxine Bonham from Monash University in Australia said it showed there is "no simple solution" to the obesity epidemic.
They said the UK's state-funded National Health Service (NHS) should be aware of the level of investment needed to develop an expert workforce to manage the problem of obesity, and said it could learn a great deal from commercial companies about how to deliver what consumers want.