The development, implementation, and evaluation of a co-designed peer education intervention to improve parents' feeding practices and diet quality of infants/children aged 0-3 years

Infancy and early childhood are crucial periods for establishing health-promoting dietary patterns and food-related behaviours that can reduce lifestyle-related disease risk. Once established in childhood, eating habits can persist throughout life, making early dietary influences particularly impactful. Parents' child feeding practices (PCFP) during these stages play a significant role in either supporting or hindering the development of healthy eating habits in children. These include poor self-regulation of food intake, eating in the absence of hunger, rejection of healthful foods, a preference for energy-dense, nutrient-poor foods, and issues such as food anxiety and avoidance. Early life nutrition interventions aiming to improve dietary intake need to incorporate behavioural strategies to help parents translate their healthy feeding intentions into practical actions. New parents have limited access to support to guide them through the complexities of the first years of feeding, often relying on ingrained generational practices. Common sources of child feeding and nutrition information for parents include friends, family, the internet, and smartphone applications. However, the abundance of online information can lead to confusion among well-intentioned parents. The PICNIC model was developed in response to insights gained from the Food For Kids Mid North Coast (FFKMNC) pilot study. This study found peer-to-peer education was an acceptable method for disseminating evidence-based infant nutrition and child feeding messages among new parents. The PICNIC project comprises a 2-hour dietitian facilitated training workshop for peer educators to share nutrition and feeding messages within their social circles. After attending a workshop peer-educators can opt-in and access ongoing digital support, including Facebook public and closed groups, a website resources repository and virtual dietitian facilitated follow-up meetings. This thesis by publication comprised four studies, with the primary aim to determine the extent to which a real-world, peer education health promotion project, informed by evidence-based research methodologies influences the child feeding practices of parents with young children, within an Australian regional and rural public health service district setting.

Firstly, a study protocol was developed to describe the methods for implementing and evaluating the effectiveness and user acceptability of PICNIC, a peer educator model incorporating online and social media components. Insights from the FFKMNC study that shaped the PICNIC model included early recruitment (before the child is six months old), focusing on feeding practices that promote healthy eating behaviours, enhancing access to online content via social media, and creating a project-specific website managed by a Health Promotion Team within a Health Service framework.

The second study aimed to refine the PICNIC project implementation model and research methods to better address the child feeding needs of rural parents and infants, with the goal of improving children's dietary intake and feeding outcomes. Over three years, 269 parents of infants aged birth to two years participated as co-researchers in a Participatory Action Research (PAR) study. Data was collected from focus groups, online meeting transcripts, social media interactions, correspondence, and field notes. Structured content analysis after each PAR cycle guided the subsequent phases of the model. The key findings of this study were that parents were more receptive to being 'feeding champions' rather than formal peer educators, quantitative data collection was most effective when integrated into program implementation, and the PAR methodology suited the dynamic real-life setting, enabling significant improvements to the intervention model and data collection methods.

The third study evaluated the impact of 12 months of participation in the PICNIC project on the feeding practices of parents and caregivers at six and 12 months, as well as the diet quality of their children 24 months after baseline. A total of 263 parents of infants up to two years old (mean age: 8.4 months) participated in a 12-month, single-arm pre-post intervention that included workshops, online meetings, a project-specific website, and social media. Parents' feeding practices were measured at baseline, six months (n=154), and 12 months (n=110), while child diet quality was assessed at 24 months (n=89). The effectiveness of the PICNIC intervention was demonstrated by significant within-participant improvements over 12 months in Family Meal Environment (0.46 [0.31, 0.62], p<0.001), Parent-Led Feeding (-0.54 [-0.66, -0.39], p<0.001), Using Food to Calm (-0.37 [-0.51, -0.23], p<0.001), and Food Rewards (-0.30 [-0.49, -0.06], p<0.05). Persuasive Feeding improved over six months (-0.28 [-0.36, 0.11], p<0.001) but not at 12 months. Changes in PICNIC participants' feeding practices also compared to age-matched historical controls. Changes in feeding practice construct scores were significantly higher (all p<0.001) at six and 12 months from baseline in Parent-Led Feeding, Persuasive Feeding, and Feeding on Demand. At 12 months from baseline the constructs of Food Rewards (p<0.001), Family Meal Environment (p<0.01), and Food to Calm (p<0.05) also improved compared with age-matched historical controls. At 24 months (mean age 34 months), the children's mean vegetable diet quality score was significantly higher (p<0.05) than age-matched historical controls.

The fourth study in this thesis examined web and social media analytics to evaluate the reach and user engagement with PICNIC's online components. This study was not part of the initial plan, but due to the success of the social media strategy, its inclusion was necessary. Online user activity data from the PICNIC Facebook closed group and public page were collected via Facebook Insights, while website traffic data was gathered through Google Analytics. Data from November 2019 to April 2021 were analysed using visualisation and summary statistics to assess program growth, reach across Australia, compare audience demographics, and explore parents' engagement with PICNIC content. Results indicated steady program growth over 18 months, with participant numbers increasing from 102 to 261 peer educators and the Facebook page audience tripling to 1,615 followers. Intervention posts shared on Facebook (4-5 posts per week) typically reached only a fraction of PICNIC Page followers each week but extended to a broader audience through their friends. Facebook posts reached 1136 users and were engaged with 19 times per week. The project-specific website had a total of 9777 visits and averaged 65 new users per week over the 18-month data collection period. The strategy of directing interested parents from social media to the website for program sign-up proved effective. Data-driven insights have informed refinements to PICNIC's digital strategy, which has enhanced website and social media engagement. Analysis of user activity has helped the PICNIC project team to optimise post timing for maximum visibility, extending reach beyond recruited participants and attracting a broader demographic, including more men (1.5 % to 14% of users) and a wider age range (49% of all Facebook users above 35 years compared to 22% of peer educators). Over 18 months, the number of peer educators grew by 166%, from 102 to 261, while the PICNIC Facebook Page audience increased by 200% to 1615 followers. Intervention posts (4–5 per week) engaged core followers and reached a broader audience through secondary exposure. Growth has continued beyond the study period, with 691 active group members and 3,476 Page followers at time of writing (March 2025).

This research successfully developed a co-designed intervention targeting parents' feeding practices and the diet quality of their infants and young children. The intervention's effectiveness in positively influencing parents' feeding practices and diet quality has led to its adoption and scaling into other areas, embedding its practices within broader community settings. PICNIC has expanded into four additional local health districts (Central Coast, Western NSW, Illawarra, and Port Stephens). Expansion into Early Education and Care (ECEC) settings emerged from parent and educator demand for consistency in feeding practices between settings. To enhance accessibility, PICNIC 'Tucker Time' and PICNIC 'Supported Playgroups' were developed to address cultural, linguistic, and socio-economic barriers, including food insecurity and trauma.

Collaboration between health professionals and parents was key to achieving the intervention's outcomes and research objectives. This partnership highlights the power of co-design in creating relevant and impactful health interventions, ensuring greater acceptance and adherence. The intervention's multi-strategy approach, utilising contemporary health communication tools, positively influenced child feeding practices and improved young children's diet quality. Peer education and social networks proved effective for disseminating evidence-based information. Additionally, web and social media analytics provided valuable insights for refining program strategies. Future research should assess whether the reported feeding practice changes influence child health up to age five, validating the intervention's long-term impact. This work contributes to the improvement of child feeding practices and sets a foundation for future innovations in community-based health interventions.