Who responds to financial incentives for weight loss? Evidence from a randomized controlled trial

Abstract

There is a paucity of evidence on the heterogeneous impacts of financial incentives on weight loss. Between March 2010 and January 2012, in a randomized controlled trial, we assigned 700 obese persons to three experimental arms. We test whether particular subgroups react differently to financial incentives for weight loss. Two treatment groups obtained a cash reward (€150 and €300 with 237 and 229 participants, respectively) for achieving an individually-assigned target weight within four months; the control group (234 participants) was not incentivized. Participants and administrators were not blinded to the intervention. We find that monetary rewards effectively induced obese individuals to reduce weight across all subgroups. However, there is no evidence for treatment-effect heterogeneity for those groups that were incentivized. Among those who were in the €300 group, statistically significant and large weight losses were observed for women, singles, and those who are not working (all above 4 kg in four months). In addition, the magnitude of the reward matters only for women and migrants. The effectiveness of financial incentives to reduce weight nevertheless raises sensitive ethical issues that should be taken into consideration by policymakers. In a randomized controlled trial involving 700 obese persons assigned to three experimental arms, we test whether financial incentives have heterogeneous effects over subgroups on weight reduction. Two treatment groups obtained a cash reward (€150 and €300 with 237 and 229 participants, respectively) for achieving an individually-assigned target weight within four months; the control group (234 participants) was not incentivized. Participants and administrators were not blinded to the intervention. We find that monetary rewards effectively induced obese individuals to reduce weight across all subgroups. However, there is no evidence for treatment-effect heterogeneity for those groups that were incentivized. Among those who were in the €300 group, statistically significant and large weight losses were observed for women, singles, and those who are not working (all above 4 kg in four months). In addition, the magnitude of the reward matters only for women and migrants.

Financial incentives for objectively-measured physical activity or weight loss in adults with chronic health conditions: A meta-analysis

“…Nine trials recruited overweight or obese subjects,[ 51 – 58 ] one recruited patients with sedentary lifestyles,[ 50 ] and one recruited subjects with osteoarthritis. [ 47 ] Four trials recruited participants from a workplace,[ 45 , 53 , 54 , 56 ] three from hospitals,[ 47 , 52 , 58 ] two from the community,[ 50 , 51 ] and one each from a rehabilitation clinic[ 55 ] and university. [ 57 ] Table 1 describes study characteristics (see Table B in S1 File for a more comprehensive summary of study details).…”

“…Of the 11 included studies (19 intervention arms), two studies (two intervention arms) intended to increase PA,[ 47 , 50 ] while nine studies (17 intervention arms) aimed to promote WL. [ 45 , 51 – 57 ] Of 19 FI intervention arms in 11 studies, eight had gain incentive schemes,[ 45 , 47 , 50 , 51 , 55 , 56 ] two implemented loss incentive schemes,[ 53 ] six utilized deposit contracts,[ 52 , 54 , 58 ] two used lottery schemes,[ 56 , 58 ] and one used a combination of gain incentive and lottery. [ 51 ] The derivation of the total amount of FI a subject could earn, adjusted to 2016 USD, is described in the Supporting Information (Table D in S1 File ).…”

Behavioural incentive interventions for health behaviour change in young people (5–18 years old): A systematic review and meta-analysis

“…Maintained behaviour change could be possible if BIs are in place for a sufficient period of time to create habits (Oliver and Brown, 2012), yet the appropriate length of time is unclear. It has been proposed that people do not always act in the way that they want, so BIs could provide motivation to behave in a way that accurately represents their long-term goals, enhancing autonomy (Kimmel and Troxel, 2012;Marteau et al, 2009;Paloyo et al, 2015), and eliminating social pressures from peers' potentially negative reactions (Wolff, 2014). Consequently, what is intrinsically desired can be attempted under the guise of an extrinsic motivator (Kifmann, 2014).…”

Data from a Randomized Experiment: Financial Incentives on Weight Loss (RWI-Obesity)

“…The majority of health costs can be linked to obesity: overweight or obese persons have a higher risk of getting type 2 diabetes, a heart disease, a hypertensive disease, a stroke, cancer, and osteoarthritis. In addition to these impairments to health, overweight may diminish psychological health and personal quality of life (Paloyo et al 2015). This article describes individual-level data of a randomized experiment to examine whether obese people are more likely to reduce weight when receiving financial incentives.…”

“…In addition, adolescents with a migration background have a higher risk of becoming obese than natives. Several studies have shown that obese people exhibit a substantially lower employment probability than healthy-weighted people (see e. g. Bertola et al 2001;Morris 2007;Lindeboom et al 2010;Caliendo/Lee 2011;Reichert 2012, Paloyo et al 2015.…”