Cash and no-cash incentives
The study tracked a year of weight loss of 668 low-income Hispanic men and women (ages 18 – 70) whose average starting weight was 98,9 kg. All participants were randomly assigned to receive one of 3 sets of incentives.
- Resource-only group – Participants were given a 1-year of Weight Watchers membership, self-monitoring tools (Fitbit, scale, food journal), health education, and monthly one-on-one check-ins. No financial incentive was given.
- Outcome-based incentives – Participants received the same as the resource group plus financial incentives linked to a percentage of weight lost. The goal was 5% of starting body weight.
- Goal-based incentives – Participants received the same as the resource group plus financial incentives linked to reaching weight-loss behaviour goals (attending 2 weight-loss counselling classes per month, weighing themselves 3x per week, exercising for 75 minutes per week).
For participants in the two groups receiving financial incentives, payments were made monthly as weight was lost or goals were met.
Giving money for weight lost is the most effective short term
The results of the study showed that financial incentives tied to losing body weight were the most effective over the short term. An impressive 49% of those in this group lost the desired 5% of body weight after 6 months. But this number dropped to 41% after a full year. Participants in this group received on average $440 in total.
Receiving money for reaching weight-loss behaviour goals was slightly less effective in the short term. Only 39% of participants in this group lost 5% of their starting weight after 6 months but this number climbed to almost 42% at the 1-year follow-up. Participants in this group received on average $303 in total.
Only 20% of those who received no financial incentives, only free resources, managed to lose the 5% of starting body weight. This number increased to nearly 33% at the 1-year mark.
“Our study provides firm evidence that offering incentives, especially cash rewards, even if only for 6 months, helps people of limited means struggling with obesity to lose weight. However, any kind of incentive to lose weight can work, even if it is just offering the tools to help do so,” said study senior investigator Melanie Jay, MD.
Focusing on behaviours, not just weight, may be better long term
The study suggests that at around 1 year, those who were incentivised to improve their weight loss behaviours started doing better than those who were simply paid for the weight they managed to lose. This would mean that with a long-term view in mind, it may be better to shift focus from weight to behaviour. But the study’s authors warned that more research is needed to say if the financial incentives would be effective for longer than one year. Some “booster” incentives may be needed to sustain the healthy weight.
It’s clear that for low-income populations, monetary incentives are much more effective than just getting education and resources for weight loss. Would that work for you? Would you join a weight-loss programme like that?