Spring has not exactly sprung yet… but you’d never know it from all the ads for weight-loss plans warning us that bathing suit season is coming. If you’ve got weight to lose, perhaps you are wondering whether joining some sort of program might be worth your time and money. But which kind is most effective? Well, some researchers in the UK were wondering the same thing—and now they’ve completed the research that gives the answer.

Their study was published in BMJ in November 2011. It measured the relative success rates of different approaches to helping overweight and obese people lose weight—and the results are quite illuminating!


Researchers enrolled 740 overweight and obese men and women (average age 49). Each joined one of the following weight-loss programs for the 12-week study, and each program was free to the participant…

• A commercial, group-based weekly program. Participants were assigned to either Weight Watchers (the same program available in the US) or one of two popular UK-based programs that are similar, Slimming World or Rosemary Conley. All three programs provided printed diet and exercise guidelines, advice, group meetings, scheduled weekly weigh-ins and feedback. When group members lost a certain amount of weight, there were rewards, such as certificates and recognition in front of the group.

• A dietitian-developed, group-based weekly program. The program structure is similar to a commercial program in that it is group-based and there were some weigh-ins, though just one at the beginning and one at the end. It was developed by dietitians and led by dietetic assistants. There weren’t as many supportive printed materials or rewards, and less attention was given to each participant. These participants met weekly for six weeks and then had follow-up sessions during week nine and week 12.

• A series of one-on-one meetings with a nurse who had been tutored in a three-day weight-management counseling course. The content of these meetings was shaped by the participant’s particular experiences and questions, so the leaders provided individualized support and education, but there were no group interactions. The leaders of these groups didn’t have extensive training in weight loss. Participants were weighed each week.

• A series of one-on-one meetings with a pharmacist who had been tutored in a three-day weight-management counseling course. This program was identical to the kind with the nurse, except that it was led by a pharmacist.

• A control group. These participants were each given passes that were good for 12 sessions at a gym but no specific advice about how to exercise, eat nutritiously or lose weight.

Every program encouraged participants to lose weight, with many asking participants to target losing 5% to 10% of their body weight, but each individual set his or her own goal. Now, let’s see which groups succeeded and which didn’t…


Researchers evaluated participants’ weight loss twice—once at the end of the 12-week program and then again at the end of one year. Every single group (including the control group that went to the gym) had lost weight at both the 12-week and the one-year marks, but the group-based programs outshone both the control group and the one-on-one programs. The commercial programs—Weight Watchers, in particular—were most effective. For instance, after one year…

Weight Watchers participants maintained an average loss of 7.62 pounds, compared with 5.40 pounds for the dietetic assistant-led group… 2.38 for the control (gym pass) group… 1.82 for one-on-one sessions with a nurse… and 1.45 for one-on-one sessions with a pharmacist.


I spoke with the study author, Kate Jolly, PhD, senior clinical lecturer in public health and epidemiology at University of Birmingham in England, who identified a number of factors that she thought may explain why the commercial programs got the gold medal, why the dietetic-assistant led program got the silver medal and why the one-on-one programs came in dead last—surprisingly, even behind the control group!

• Group support. Certainly not every person is comfortable talking about his/her weight in front of other people, but many folks find that the dynamics of group support—especially the commercial programs, with their cheers and certificates for weight loss and their sympathy for tougher times—is helpful. Both the commercial diets and the dietetic assistant-led programs provided group support.

• Convenience. Commercial programs are held at multiple locations and provide lots of meeting times to choose from, including day and evening options. The dietetic assistant-led program and one-to-one nurse-led and pharmacy-led programs met only during the day and in only one location. Dr. Jolly said that participants weren’t as likely to attend the one-on-one sessions because they needed to schedule their own appointments—sometimes they just didn’t follow through.

• Reinforcement. Commercial programs offer information in many formats including printed diet and exercise advice and other at-home resources such as helpful Web sites and Web-based or telephone support—none of which were available through the other programs. These may have reminded participants to stay on track.

• Regularly scheduled weigh-ins. Dr. Jolly pointed out that since patients scheduled their own weigh-ins for the one-on-one programs, they were free to manipulate their appointments to gloss over, say, a weekend food splurge. The dietetic assistant-led group had only two weigh-ins. But the commercial programs had both the highest number of weigh-ins and the most strictly scheduled ones—and since they were less flexible, they likely promoted more accountability.

So if you’re thinking about choosing a weight-loss program, this research suggests that you may want to consider a commercial program first—but keep in mind, said Dr. Jolly, that every person is different, so be patient until you find something that works for you.