TY  - JOUR
T1  - Financial incentive–based approaches for weight loss: A randomized trial
AU  - Volpp KG, John LK, Troxel AB, Norton L, Fassbender J, Loewenstein G
Y1  - 2008/12/10
N1  - 10.1001/jama.2008.804
JO  - JAMA
SP  - 2631
EP  - 2637
VL  - 300
IS  - 22
N2  - Context 
                  Identifying effective obesity treatment is both a clinical challenge and a public health priority due to the health consequences of obesity.Objective 
                  To determine whether common decision errors identified by behavioral economists such as prospect theory, loss aversion, and regret could be used to design an effective weight loss intervention.Design, Setting, and Participants 
                  Fifty-seven healthy participants aged 30-70 years with a body mass index of 30-40 were randomized to 3 weight loss plans: monthly weigh-ins, a lottery incentive program, or a deposit contract that allowed for participant matching, with a weight loss goal of 1 lb (0.45 kg) a week for 16 weeks. Participants were recruited May-August 2007 at the Philadelphia VA Medical Center in Pennsylvania and were followed up through June 2008.Main Outcome Measures 
                  Weight loss after 16 weeks.Results 
                  The incentive groups lost significantly more weight than the control group (mean, 3.9 lb). Compared with the control group, the lottery group lost a mean of 13.1 lb (95% confidence interval [CI] of the difference in means, 1.95-16.40; P=.02) and the deposit contract group lost a mean of 14.0 lb (95% CI of the difference in means, 3.69-16.43; P =.006). About half of those in both incentive groups met the 16-lb target weight loss: 47.4% (95% CI, 24.5%-71.1%) in the deposit contract group and 52.6% (95% CI, 28.9%-75.6%) in the lottery group, whereas 10.5% (95% CI, 1.3%- 33.1%; P = .01) in the control group met the 16-lb target. Although the net weight loss between enrollment in the study and at the end of 7 months was larger in the incentive groups (9.2 lb; t = 1.21; 95% CI, −3.20 to 12.66; P = .23, in the lottery group and 6.2 lb; t = 0.52; 95% CI, −5.17 to 8.75; P = .61 in the deposit contract group) than in the control group (4.4 lb), these differences were not statistically significant. However, incentive participants weighed significantly less at 7 months than at the study start (P = .01 for the lottery group; P = .03 for the deposit contract group) whereas controls did not.Conclusions 
                  The use of economic incentives produced significant weight loss during the 16 weeks of intervention that was not fully sustained. The longer-term use of incentives should be evaluated.Trial Registration 
                  clinicaltrials.gov Identifier: NCT00520611
SN  - 0098-7484
M3  - doi: 10.1001/jama.2008.804
UR  - http://dx.doi.org/10.1001/jama.2008.804
ER  -