Purpose: To pilot a community-based, localised lifestyle medicine intervention for improving residents' mental health, wellbeing and resilience.

Background: Mental health is deteriorating globally, exacerbated by the COVID-19 pandemic and its residual effects. There is an urgent need to provide large-scale interventions that equip the general population with knowledge and skills to improve their mental health, wellbeing and resilience. Disseminating lifestyle medicine interventions through local governing authorities may provide an efficient model for achieving community-wide impact.

Methods: Avondale University and Lake Macquarie City Council (LMCC), located in Australia, partnered to offer a free, online, seven-week, lifestyle-based mental health promotion program to all residents of the LMCC during a COVID-19 lockdown. LMCC promoted the program through established networks and 2390 households registered—4041 participants. In a mixed-methods design, 138 participants responded to a post-program survey that included questions and statements (using Likert scales) about: their perceived mental wellbeing before and after the program; the program's effect on self-efficacy for managing mental health; and program satisfaction. Qualitative questions probed participants' likes and dislikes and were analysed thematically.

Results: The majority (89%) of respondents reported that participating in the program improved their mental health, and 99% indicated they would recommend the program to a friend. While 37% rated themselves as having either 'poor' or 'fair' mental health at the beginning of the intervention, only 6% reported being in that range on completion. Most respondents (94%) believed they gained skills to help them manage their wellbeing, and 91% perceived the learnings would continue to impact their mental health positively. Themes generated from the qualitative data showed that most participants liked the video content and delivery style, community camaraderie, growth in personal empowerment, and accessibility. Some participants did not find accessibility easy, disliked the delivery style, and experienced technical difficulties.

Conclusions: The community-based, online, localised lifestyle medicine intervention improved residents' perceived mental health and skills for future mental health management. Overall, participants were satisfied with the intervention and valued the content, community togetherness and emphasis on self-empowerment.