Confidence boost linked to weight loss in smartphone trial

The results emerge from the world-first TXT2BFiT intervention, developed by researchers at the Charles Perkins Centre, which targeted young people at risk of obesity to improve their diet and exercise behaviours through tailored prompts on their smartphones.

This latest study investigated which motivating factors in the pilot mediated the greatest health outcomes, with the results published in the latest edition of Appetite journal.

Participants in the trial who reported greater self-efficacy – a belief in one's ability to succeed – were most likely to improve their health scores, particularly when increasing fruit and vegetable intake and reducing their sugar-sweetened beverage (SSB) 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."

Mobile phones for weight loss

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 aged between 18- and 35-years-old 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.

Surprisingly, the smartphone app was found to be the least used method in the trial, with less than 25 percent 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' self-efficacy in performing the targeted behaviours," said Ms Partridge.

Overall results from the TXT2BFiT program, published earlier this year in JMIR mHealth 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 SSB and take-out 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."

Key facts:

• Self-efficacy accounted for a 37 percent increase in vegetable consumption, 25 percent increase in fruit consumption, 10 percent reduction in SSB intake and 27 percent decrease in takeaway meal consumption at nine months
• Currently more than two-thirds of young Australians aged 18-35 are overweight or obese
• Only 3.2 percent of 18-24 year-olds meet recommended fruit and vegetable intake guidelines
• Forty-seven percent of young adults do not achieve recommended daily physical activity levels