250 young people aged 18 to 35 recently completed the the world's first "TXT2BFiT" intervention, a program where they received calls, texts and emails in an effort to work out which was the most encouraging.
The research, developed at the Charles Perkins Centre in Sydney, showed that a call or text to get moving and eat healthy was far more beneficial than a reminder from an app.
Unsurprisingly, participants in the trial who reported a greater self-belief in their ability to succeed were most likely to improve their health scores, particularly when increasing fruit and vegetable intake and reducing their sugar-sweetened beverage consumption.
"While previous studies have used smartphone platforms to drive physical activity and improve dietary behaviours, none have really considered the underlying behaviourial mechanisms which motivate such changes," said lead author Stephanie Partridge, a PhD candidate at the Charles Perkins Centre.
"Understanding what drives young people to change their eating and physical activity behaviours is essential in order to create more effective health interventions on emerging platforms, including websites and smartphones."
The TXT2BFiT intervention was developed by Professor Margaret Allman-Farinelli, who leads the Wireless Wellbeing and Personalised Health research node at the Charles Perkins Centre, and her colleagues. The program aimed to help young people on multiple health fronts: to reach their recommended daily servings of fruit and vegetables, reduce their soft drink and take-away consumption and increase their physical activity levels.
The 250 participants were recruited to the trial for being at risk of developing obesity, and were placed into either an intervention or control group. Over 12 weeks they received a mix of personalised calls and texts, weekly reminder emails, access to self-monitoring smartphone apps and e-booklets on nutrition, physical activity and budget eating tips.
Participants completed online surveys at the start of the study, after the three-month intensive phase and at the completion of a six-month maintenance phase to reveal which measures were the most important in helping to improve diet and exercise habits.
Surprisingly, the smartphone app was found to be the least used method in the trial, with less than 25 per cent of participants reporting this tool was beneficial.
"Participants reported that text messages and coaching calls were the most used and helpful components, with both aiming to increase participants' [confidence] in performing the targeted behaviours," said Ms Partridge.
"Despite the convenience of smartphone apps, most of the participants reported they still preferred the texts and coaching calls, which not only made them feel more accountable but also encouraged them to believe in their ability to change."
Overall results from the TXT2BFiT program showed that after the three-month phase those in the intervention group weighed 3.7kg less than those in the control group, and also managed to maintain this weight loss at nine months. Intervention participants had greater odds of meeting daily recommendations for fruit and vegetables, and decreased their sugar and take-away meal consumption.
"Young adults face a great deal of social influence on their diet and exercise patterns, and understanding what motivates these behaviours is critical when designing targeted health interventions," said Professor Margaret Allman-Farinelli.
"These insights will help us to refine future mobile health platforms to more effectively target young adults from different educational and geographic backgrounds. The behaviours set in adolescence and the early twenties may solidify into adulthood, so by improving health behaviours at a younger age we can help set people up for a lifetime of good health."