WEDNESDAY, September 7, 2011 (Health.com) — Overweight and obese adults who followed the Weight Watchers program lost more than twice as much weight as those who received weight-loss advice from a doctor or nurse, according to a new yearlong study funded by the company.
The study, which was published today in the Lancet, included 772 men and women in Australia, Germany, and the UK who were recruited during ordinary doctor’s appointments. The researchers randomly selected about half of the participants to receive a free 12-month Weight Watchers membership (including access to weekly meetings), and encouraged the other half to attend monthly one-on-one weight-management sessions at their doctor’s office.
The 61% of Weight Watchers users who stuck with the program for a full year lost 15 pounds, on average, compared to 7 pounds among the 54% of people in the other group who continued to visit their doctors each month. When the researchers included the people who dropped out of either program before the year was up, the average weight loss was lower but followed the same pattern: 11 pounds in the Weight Watchers group and 5 pounds in the other group.
Michael Jensen, MD, an endocrinologist at the Mayo Clinic, in Rochester, Minn., says it’s only natural that the weekly weigh-ins and “group spirit” of programs such as Weight Watchers would prove more effective than occasional guidance from a doctor or nurse, since research has shown that dieters are more likely to stick with weight-loss programs that stress accountability.
“It’s not terribly surprising that a group whose whole career is basically helping people with weight management would do a better job than a primary-care group that has a lot more responsibilities on top of that,” says Dr. Jensen, who was not involved in the study.
Similar studies of other commercial weight-loss systems, such as Jenny Craig and prepackaged food programs, have produced comparable results in the past. In a 2010 study funded by Jenny Craig and published in the Journal of the American Medical Association, for instance, women who completed one year of the program lost about 20 pounds, three or four times more than women who received occasional advice from a nutritionist.
Still, the authors of the new study say they were surprised by how dedicated the Weight Watchers participants were—they attended three meetings a month, on average—and by how much weight they actually lost.
“I don’t think we could have predicted that people randomly allocated to Weight Watchers by their doctor—rather than choosing to attend of their own accord, which would give a selected group of probably more motivated people—would lose significantly more weight,” says lead author Susan Jebb, PhD, a diet and population health researcher at the UK Medical Research Council, in Cambridge.
People may be more likely to stick with a program like Weight Watchers when they’re participating free of charge, however. The cost of Weight Watchers can run as high as $500 per year, a price tag that could sap the motivation of real-world dieters who are paying out of pocket. At the same time, Jensen says, it’s possible that some people paying out pocket might be less likely to drop the program because they’d feel obligated to get their money’s worth.
Next page: “Medically significant” weight loss
