Financial incentives for extended weight loss: a randomized, controlled trial.
BACKGROUND
Previous efforts to use incentives for weight loss have resulted in substantial weight regain after 16 weeks.


OBJECTIVE
To evaluate a longer term weight loss intervention using financial incentives.


METHODS
A 32-week, three-arm randomized controlled trial of financial incentives for weight loss consisting of a 24-week weight loss phase during which all participants were given a weight loss goal of 1 pound per week, followed by an 8-week maintenance phase.


METHODS
Veterans who were patients at the Philadelphia Veterans Affairs Medical Center with BMIs of 30-40.


METHODS
Participants were randomly assigned to participate in either a weight-monitoring program involving a consultation with a dietician and monthly weigh-ins (control condition), or the same program with one of two financial incentive plans. Both incentive arms used deposit contracts (DC) in which participants put their own money at risk (matched 1:1), which they lost if they failed to lose weight. In one incentive arm participants were told that the period after 24 weeks was for weight-loss maintenance; in the other, no such distinction was made.


METHODS
Weight loss after 32 weeks.


RESULTS
Results were analyzed using intention-to-treat. There was no difference in weight loss between the incentive arms (P = 0.80). Incentive participants lost more weight than control participants [mean DC = 8.70 pounds, mean control = 1.17, P = 0.04, 95% CI of the difference in means (0.56, 14.50)]. Follow-up data 36 weeks after the 32-week intervention had ended indicated weight regain; the net weight loss between the incentive and control groups was no longer significant (mean DC = 1.2 pounds, 95% CI, -2.58-5.00; mean control = 0.27, 95% CI, -3.77-4.30, P = 0.76).


CONCLUSIONS
Financial incentives produced significant weight loss over an 8-month intervention; however, participants regained weight post-intervention.
Department of Social and Decision Sciences, Carnegie Mellon University, 208 Porter Hall, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA. lkjohn@andrew.cmu.edu
Leslie K
LK
John
George
G
Loewenstein
Andrea B
AB
Troxel
Laurie
L
Norton
Jennifer E
JE
Fassbender
Kevin G
KG
Volpp
D000328:Adult; D000368:Aged; D001835:Body Weight / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006787:Hospitals, Veterans / Q000191:economics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009042:Motivation / Q000502:physiology; D009765:Obesity / Q000191:economics* / Q000523:psychology / Q000628:therapy*; D012201:Reward; D013997:Time Factors; D015431:Weight Loss / Q000502:physiology
Psychol Bull. 1975 Jul;82(4):463-96
1099599
JAMA. 2007 Nov 28;298(20):2415-7
18042920
JAMA. 2008 Dec 10;300(22):2631-7
19066383
JAMA. 2003 Apr 9;289(14):1792-8
12684357
Health Psychol. 2000 Jan;19(1S):5-16
10709944
Cogn Psychol. 1999 Feb;38(1):48-78
10090798
N Engl J Med. 2002 Feb 7;346(6):393-403
11832527
Control Clin Trials. 2003 Oct;24(5):610-28
14500058
Behav Res Ther. 1978;16(5):363-9
743075
Accid Anal Prev. 1985 Apr;17(2):119-33
4096780
J Behav Med. 1987 Oct;10(5):481-500
3430590
Psychol Sci. 2002 May;13(3):219-24
12009041
JAMA. 2006 Apr 5;295(13):1549-55
16595758