LiveBetterSA: Comparing AI-Enhanced Lifestyle Coaching Using a Generative Large Language Model vs. Traditional Telephone Coaching for Adults

Participants in the digital health coaching group will engage with a digital health coach for six months via the LiveBetterSA responsive web application. The digital health coaching system, developed using OpenAI's large language model and customised by the University of South Australia and AndMine Pty Ltd, will provide personalised onboarding, guided goal setting, and feedback. The system will be accessible 24/7, allowing participants to interact with the digital health coach at their convenience. Optional Fitbit integration will enable automated step tracking. Participants will receive digital scales and a measuring tape for self-monitoring and outcome reporting. Participants are encouraged to engage with the platform daily, including asking for advice, responding to coaching prompts, reviewing goals, and receiving personalised feedback. The goal progress check-in schedule is customisable, selected by participants during onboarding, with options ranging from daily, every other day, twice weekly, weekly, or every two weeks. Personalisation occurs through participant-entered data collected during onboarding, including demographic information, anthropometric measurements, health history, physical activity patterns, dietary habits, eating behaviours, and personal motivations. This data informs tailored goal recommendations, feedback pathways, and support strategies, dynamically adjusted as participants engage with the platform over time. The guidance provided by the digital health coach is based on comprehensive training content sourced from evidence-based national and international guidelines, educational materials, and reputable health organisations. Key sources informing the AI's content include the Australian Dietary Guidelines (NHMRC) and Australian Physical Activity Guidelines (Department of Health and Aged Care), World Health Organization (WHO) guidelines, as well as educational resources from Diabetes Australia, the Heart Foundation, Cancer Council, Healthy Bones Australia, Exercise and Sports Science Australia (ESSA) and others. This ensures that the support offered is evidence-based, credible, and aligned with national and international public health recommendations. Content includes practical guidance on healthy eating, physical activity, cardiovascular health, digestive health, osteoporosis prevention, stress management, sleep hygiene, and the mental health benefits of exercise. The digital health coach provides guidance using structured conversational techniques based on participant data, aligned to health guidelines. For example: -After assessing vegetable intake, the coach offers tailored encouragement compared to the Australian Dietary Guidelines (e.g., highlighting strengths first, then suggesting simple improvements if vegetable serves are below recommendations). -Following assessment of physical activity levels, the coach compares current behaviour to national activity guidelines and offers achievable next steps (e.g., suggesting an additional walk if a participant is close to but below 150 minutes per week). -If a participant shares lower confidence or motivation, the coach adapts by suggesting smaller, habit-based goals rather than outcome-based goals (e.g., starting with 5–10 minutes of activity rather than full sessions). Goal-setting follows a structured process: Up to three goal areas are suggested based on participant priorities and opportunities for improvement, participant's select their preference or propose their own. Goals are personalised to the participant's lifestyle context, such as their available time, preferred activities, and readiness for change. Participant engagement is monitored through backend system APIs, with automated reporting of usage metrics. Participants with declining engagement patterns are sent supportive re-engagement emails encouraging continued involvement. Strategies to monitor adherence include: -Login success events (first and subsequent logins), -Page view tracking across the app, -Click tracking for key actions such as goal setup, health check completion, and dashboard/menu interactions, -Monitoring of review of check-in summaries, -Recording the frequency of check-ins (based on the participant-selected schedule), -Average session duration calculated from time spent within the platform.