An after dinner or bedtime snack can be hard to resist, but could a gentle nudge from a smartphone app help people with type two diabetes to quit the common habit?
Led by researchers at Adelaide University and Flinders University, a smart phone app with image-based reminders was developed and then trialled to see if it could help people with type two diabetes avoid snacking after dinner.
More than 60 South Australians with type two diabetes who regularly snacked at night took part in a micro-randomized trial, an emerging study design in which each participant is randomized repeatedly over time rather than once.
Every evening for two weeks, the app randomly decided whether to send each person a nudge 30 minutes after dinner, allowing researchers to compare nights with and without a reminder for the same individual.
“Late night snacking has negative impacts on blood sugar levels in people living with type two diabetes,” said lead author Professor Gary Wittert from Adelaide University and the South Australian Health and Medical Research Institute (SAHMRI).
“We know from previous studies that digital nudges, including text message reminders, are effective at promoting healthier eating habits and we wanted to see if the benefits could extend to people with type two diabetes.
“What we found was our ’just in time’ nudges were easy to deliver and did reduce post-dinner snacking glucose spikes initially, but those early positive effects quickly faded as people became used to the messaging, indicating that the intervention has some promise but needs adjusting.”
The platform for the new app was built at the Flinders Digital Health Research Lab with the goal of delivering personalized, just-in-time reminders for people to manage their diabetes.
A total of seven different nudges were delivered through the app, suggesting healthy activities that people can do after dinner instead of snacking such as going for a walk, reading a book or choosing other healthier alternatives.
It is not about using a heavy-handed approach to change behavior, but rather providing gentle, timely reminders that encourage healthier daily routines for diabetes management,”
Dr Lijun Zhao, Study First Author and Research Fellow, Digital Health, College of Medicine and Public Health, Flinders University
“The aim is to briefly interrupt automatic, habitual decision-making processes, creating an opportunity for individuals to pause, reflect, and make healthier choices.”
Participants wore continuous glucose monitors, which recorded their blood sugar around the clock. This allowed the team to measure the effect of each individual nudge on post-dinner glucose in real time, rather than relying on self-reported snacking or long-term averages.
“Because every night was its own small experiment and glucose was tracked continuously, we could see exactly when the nudges helped, and when people stopped responding to them,” Dr Zhao said.
The study did have a high engagement rate of almost 90%, with men and younger participants more likely to view the reminders faster than women and older adults.
“The early results showed the app did work successfully for a while but the benefits weren’t sustained,” Professor Wittert said.
“We need to explore ways of making the app more effective through personalization, improving the timing of message delivery and preventing message fatigue.”
The researchers say this approach of testing digital prompts in real time against objective sensor data could be used to fine-tune interventions for many chronic conditions, not just diabetes.
"Further research will look at more ways to improve long-term use and reinforce supports, including links to more useful information and scientific resources," Dr Zhao said.
The findings have been published in the journal Diabetes, Obesity and Metabolism, with researchers from Diabetes SA also contributing to the study.
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