By Genevra Pittman
NEW YORK (Reuters Health) - Researchers this week said there's not much evidence to support a common theory behind weight-loss programs known as the "stages of change" model.
The approach is based on the idea that a series of steps mark a person's transition from unhealthy to healthy behavior: pre-contemplation, contemplation, preparation, action and maintenance. Dietitians and counselors need to guide people through these stages, targeting them with messages to fit their attitude and incorporating exercise and healthier foods as they're ready for those changes.
Many people may want to lose weight -- or improve their health in other ways, such as by quitting smoking -- but are not prepared to take the first big step, said Hayden Bosworth, who studies health interventions at Duke University Medical Center in Durham, North Carolina.
In those cases, it's not going to be very helpful to give the typical motivational "weight loss is important, keep doing it and keep up the good work," he said. That message also doesn't help people who've already lost the weight and need extra help maintaining it, or preparing for specific challenges.
"Intuitively it makes sense to try to track people into the different places where they may be, and try to provide more tailored material," Bosworth, who was not involved in the new report, told Reuters Health.
Stages of change "assumes that (the) majority of people are not ready to change their behavior and therefore traditional active intervention for weight prevention programs may not be appropriate," said Nik Tuah, from Imperial College London in the UK, in an email to Reuters Health.
Also known as the transtheoretical model, stages of change is commonly used in weight-loss programs, said Tuah, one of the authors of the new report.
Weight Watchers highlights the stages of change model on its website as a way for people to "make sustained changes in health behaviors."
But in a new review of studies that compared programs based on the stages of change theory to basic care for overweight and obese people, participants rarely lost more than a few pounds. And there was no evidence that if they did lose weight, they were able to keep it off for more than a year or two.
"It is disheartening," Bosworth said. "If we're getting such minimal effects... we need to revisit these programs."
Still, Bosworth said, the new study doesn't necessarily show that the stages of change approach doesn't work. It's only a "theoretical framework" he said, and how you use it is also critical to weight-loss results.
Tuah and her colleagues looked back at five studies with a total of close to 4,000 people. They varied in the type of health interventions used, from bringing participants in for counseling sessions to giving them educational materials or a pedometer to encourage physical activity.
Weight losses averaged less than five pounds in people treated using the stages of change model -- and none of the studies tested whether any weight loss was maintained over the long run.
There was a hint, however, that tailoring to each person's "stage" helped them eat more fruits and vegetables and exercise more, the researchers noted in their report, published in the journal The Cochrane Library.
The findings aren't necessarily a knock against the stages of change theory itself, Bosworth said -- maybe just against the weight-loss interventions used to begin with.
The stages of change model can be applied to everything from public health educational materials to one-on-one counseling, he added. But regardless of the theory, "If the intervention is crappy, it's not going to work."
The researchers concluded that more studies are needed to see how stages of change can be used to trigger behavior changes and sustainable weight loss -- but that the model on its own isn't a recipe for guaranteed success.
Tuah concluded, "The evidence from this study helps to enhance patients' understanding of the effectiveness and limitations of their treatment regimes."
SOURCE: http://bit.ly/nLIR3l The Cochrane Library, online October 5, 2011.