Re: Comparison of range of commercial or primary care led weight reduction programmes with minimal intervention control for weight loss in obesity: Lighten Up randomised controlled trial
Jolly et al’s results suggest that Weight Watchers is successful at achieving weight reduction immediately after programme completion and on follow-up at one year1. We have just concluded an evaluation study of a NHS-funded Weight Watchers service which gave similar results at 23 months.
108 participants from our original pilot group, who accessed Weight Watchers in June 2009, were recently invited to return postal questionnaires requesting their current weight (43.5% return rate). This was followed-up with telephone calls and finally requests from GP records regarding non-responders (weights were accepted only if recorded within 6 months of enquiry). We successfully followed-up 81 (75%) of the cohort to an average of 693 days [s.d. 61], and excluded those lost to follow-up from further analysis. Mean weight at baseline (101.7kg [s.d. 19.4]) and at 12-week course completion (97.4kg [s.d. 19.0]) were significantly different (p<0.001) – a change of -4.3kg which almost matches Jolly et al’s finding1. Mean follow-up weight (97.5kg [s.d. 19.4]) was similar to course-end weight, and was likewise significantly different to baseline (p<0.001). These relationships were mirrored by BMI comparisons, with a significant difference between baseline BMI (38.2 [s.d. 6.4]) and both the course-completion BMI (36.6 [s.d. 6.7], p<0.001) and follow-up BMI (36.6 [s.d. 6.5], p<0.001).
Despite the obvious limitations of this small mixed-source dataset based largely on self-reported weight, these results resonate with Jolly et al’s findings and furthermore suggest that weight reduction achieved on completion of Weight Watchers is maintained to almost two years. The clinical benefit of relatively small changes in weight in people with a high BMI, and the longer-term outcomes of alternative weight loss programmes both need careful consideration before contemplating broader inclusion of Weight Watchers or other weight loss services in public health strategies against obesity.
1. Jolly K, Lewis A, Beach J, Denley J, Adab P, Deeks JJ, Daley A, Aveyard P. Comparison of range of commercial or primary care led weight reduction programmes with minimal intervention control for weight loss in obesity: Lighten Up randomised controlled trial. BMJ 2011;343:d6500
Competing interests: No competing interests