Tailored feedback to change overweight adults’ diet and physical activity behaviours.

The overall aim of this 1-year randomised controlled trial is to investigate whether diet and physical activity behaviours can be improved with a tailored intervention in an overweight population recruited through the LiveLighter social marketing campaign in Perth, Western Australia. Individuals who sign up to the LiveLighter website will be invited to participate in the study and if eligible will be randomised to one of three groups (200 per group): Arm 1: tailored feedback intervention group (TF) for six months, followed by six months maintenance; Arm 2: active control (AC) who receive no feedback on diet or physical activity behaviours but undertake the same assessments as the TF group; Arm 3: on-line control (OC) who will complete online assessments only. TF and AC will attend two face-to-face data collection visits at baseline, 6-months and again at one year, where they will be instructed on how to complete a 4-day mobile food record (mFR) using an investigator designed App running on a mobile device (iPhone or Android telephone) and record their physical activity for seven days by wearing an activity monitor. They will also have their height, weight and waist circumference measured. At the second face-to-face visit they will be interviewed to clarify the content of their food record and return their activity monitor. The same assessments will be repeated at six and 12 months. In addition, all groups will complete additional on-line assessments (demographic, psychosocial variables, food frequency questionnaire and physical activity behaviours) at baseline, six and 12 months. All groups will have access to the LiveLighter website materials throughout the intervention. The intervention content for diet and physical activity will be evidence-based (for example: the Clinical guidelines for the management of overweight and obesity in Australia, the Australian Dietary Guidelines and Australia's Physical Activity and Sedentary Behaviour Guidelines). Formative focus group studies in consumers and health professionals were conducted prior to the intervention to inform the intervention features and content. The behaviour change strategies to inform the intervention will be based on the behavioural intervention technology (BIT) framework. These include self-monitoring, goal setting, motivation enhancement and feedback. Motivation enhancements (increases the likelihood of engagement) will include positive reinforcement (in the tailoring communications) and incentives. The intervention group (TF) will be provided with a fitness tracker to monitor their daily steps for the study duration and have a mobile food record app installed on their smartphone for monitoring diet and physical activity. The intervention group (TF) will receive tailored feedback on their diet and physical activity behaviours commencing within one week of their baseline visit. Tailored dietary feedback will be based on food group analysis of 4-day mobile food record and formulated by the research dietitian. Feedback on physical activity will be from the accelerometer and fitness tracker data and formulated by the research exercise physiologist. The tailored feedback, delivered as 12 emails one week apart, will focus on key messages around their healthy eating (for example: fruits, vegetables, sugary-drinks, junk food, alcohol, portion sizes) and physical activity (for example: number of steps, sitting time, exercise intensity). Standard email templates for each topic will be developed with the dietary and physical activity feedback content personalised for each participant. The email content will be consistent with the communications for the LiveLighter campaign and will address each participants personal barriers to changing their diet and physical activity behaviours, reinforce motivation and develop skills through the meal and activity planner and healthy recipes. At 6, 12, 18 and 24 weeks intervention group participants will be prompted by the mobile food record app, to complete a 1-day food mobile record and answer daily questions on number of steps and time spent sitting in the previous day, for seven days. They will be sent re-tailored feedback, with comparison against their previous record. Other components used in tailoring will include preference for autonomy support, intention, motivation, confidence informed by self-determination theory and motivational interviewing. A process evaluation will assess to what extent the intervention reached the target audiences. A brief questionnaire will be used to evaluate the participants’ perception of the computer-tailored feedback and to comment on features they like/dislike about the program. The TF and AC groups will also provide feedback on the usability of the mobile food record app. Impact evaluation will be assessed by exit interview surveys at 14-months by telephone with the target group to assess the impact of the intervention as well as assess perceptions of the various strategies and materials.