Texting with monetary incentives helped men lose excess weight
A clinical trial by British scientists has shown that text messages with financial incentives (up to £400) sent over 12 months lead to significant weight loss in men trying to lose weight. As reported in The Journal of the American Medical Association, such messages were much more effective than conventional motivational messages about weight loss.
Although obesity increases the risk of type 2 diabetes, heart disease, stroke and mobility impairment and affects an estimated 900 million people worldwide, men are less likely than women to participate in weight loss interventions. Therefore, clinicians are developing approaches and techniques that can be used to increase men's adherence to weight loss.
Motivational text messaging may be one such tactic. A systematic review that included 12 randomised clinical trials reported that weight loss interventions based on text messaging (SMS messaging) were associated with an average weight loss of 2.3 kilograms. However, it is not entirely clear which text message stimuli can be considered the most effective.
A research team led by Pat Hoddinott from the University of Stirling investigated whether text messages with financial incentives could help obese men lose weight during a 12-month follow-up compared to a control group. This clinical trial also evaluated whether simple motivational text messages could lead to significant weight loss. A total of 585 people were included in the study: 196 were in the financial incentive text messaging group, 194 in the motivational text messaging group, and 195 in the control group. The final analyses included 426 participants.
Participants had a mean age of 50.7 years, a mean body weight of 118.5 kilograms, and a mean BMI of 37.7. The group with simple motivational text messages received emails each day that went something like this, "That's the six-month mark! Two things are important now: not to regain the weight you lost and to have a goal in mind for the year. How confident are you that you can handle it?". The financial incentive group received messages that £400 had been transferred into their account for the study, which they would be able to access at the end of the clinical trial, but this money would be forfeited if participants did not achieve the target weight loss.
The targets were weight loss of five per cent from baseline after three months (guaranteed to receive £50), 10 per cent from baseline after six months (guaranteed to receive £150) and so on. Information on the amount due was automatically calculated from weight data and sent to participants by text message after each weight assessment, and payment was made by bank transfer after the 12-month follow-up.
During the 12-month follow-up, the mean percentage change in weight was -4.8 per cent in the group where text messaging was accompanied by financial incentives, -2.7 per cent in the group where only motivational text messages were used (p = 0.05), and -1.3 per cent in the control group (p < 0.001). Participants lost an average of 5.7 kilograms in the group where text messaging was accompanied by financial incentives, three kilograms in the group where only text messages were used, and one and a half kilograms in the control group. After adjusting for obesity treatments, the impact of financial incentives remained statistically significant.
According to the researchers, these results provide a scientific rationale for an approach that can be used to achieve weight loss in men with low adherence to treatment. The researchers consider the high public health costs of this approach to be an obvious disadvantage, but more research is needed to examine the cost-effectiveness of this approach compared with the costs of obesity-associated diseases.