Measuring and Supporting Adherence to Dietary Reporting and Dietary Intervention Using a Smartphone Application in the PREDITION Trial (PRotEin DIet SatisfacTION)

Abstract

Objectives: Adherence within nutritional research studies have remained a challenge, despite technological advances. The current thesis aims to measure and support adherence to dietary intervention and adherence to dietary reporting in the Predition Trial, using a smartphone application. An exploration of the barriers to achieving optimal adherence to dietary reporting will be investigated, as will the association between baseline characteristics and adherence to dietary intervention and dietary reporting. Methods: 40 young adults (aged 20 to 35) were recruited to participate in the ten-week Predition Trial and were randomised into two dietary intervention groups: a flexitarian diet (n=20) or a vegetarian diet (n=20). Participants were required to consume all three serves of protein provided each week and record all dietary intake into the smartphone diet recording application “Easy Diet Diary (EDD).” Non-adherence to dietary intervention or dietary reporting resulted in text message reminders by the research team. Adherence to dietary intervention and adherence to dietary reporting were monitored through biweekly compliance checkups and developed into the adherence compliance score and reporting compliance score, to measure how well participants were adhering to either dietary intervention or dietary reporting. Compliance to the study was defined as adherence to dietary reporting and dietary intervention simultaneously, and was measured using a composite compliance score, which combined both adherence compliance scores and reporting compliance scores. Trends in adherence to dietary reporting, dietary intervention, and compliance, were measured as percentage of participants that did not adhere at each weekly interval. Barriers to recording into the EDD application was measured using the Barriers to Recording Questionnaire in the pilot groups (n=20) at week 5 using quantitative and qualitative analysis, and three months post intervention. Predictors of adherence to dietary reporting, adherence to dietary intervention and compliance to the study were analysed using multiple linear regression analysis. iii Results: All 40 participants completed the study and there were no dropouts. Adherence to dietary intervention and compliance to the study were both higher in the red meat intervention group and statistically significant between intervention groups. Adherence to dietary intervention and adherence to dietary reporting decreased as the study progressed, in both intervention groups, where the vegetarian group showed more non-adherence to both dietary intervention and dietary reporting. The Barriers to Recording questionnaire found: 89% of participants reported it was helpful to undergo the trial with a pair/partner, 94% of participants reported it was helpful to receive text message reminders and 100% of participants reported feeling well supported throughout the trial. Four themes were categorised from participant responses to the questionnaire: 1) Lack of functionality with the EDD application; 2) More regularity with text message reminders; 3) Lifestyle barriers; 4) Recording Inaccuracies. The Positive Eating scale was positively associated with composite compliance scores in adjusted models, demonstrating that positive eating was associated with better compliance to the study. No other baseline characteristics were associated with adherence to dietary intervention, adherence to dietary reporting or compliance to the study. Conclusions: Overall, the study was successful in measuring and supporting adherence to dietary intervention and dietary reporting in the Predition Trial, using a smartphone application. The text message reminders were a supportive strategy to improving compliance to the study and the EDD application was well accepted by participants. Interestingly, the red meat intervention group showed better adherence to dietary intervention and better compliance to the study, when compared with the vegetarian intervention group. This was related to higher baseline positive eating scores in the red meat intervention group, suggesting that relationship, enjoyment, and emotions with eating may affect an individual’s level of compliance to dietary intervention studies.