Young Australian adults are deeply concerned about the effects of climate change, and are motivated to pressure businesses and government to take action.[1] This environmental awareness presents an opportunity to engage them in healthy and sustainable dietary interventions, which can also improve their poor diet quality.[2] When designing interventions, it is important to measure changes in determinants towards adherence before and after implementation. As such, this study aimed to measure sustainable food literacy, other dietary determinants and adherence to healthy and sustainable diets in young Australian adults. Data were collected as part of a pilot healthy and sustainable nutrition intervention that aims to improve nut and legume intakes.
Tertiary students were recruited from a Victorian university. Baseline data from the intervention was collected in July 2025. A validated 26-item sustainable food literacy scale[3] measured four domains: self perceived knowledge, food skills, attitudes, action intent/ action strategies towards healthy and sustainable diets. A 7-point Likert scale was used to assess agreement with the 26 food literacy statements. The possible score range for each of the domains was 1-7, with a higher score indicating higher adherence to the domain. Other determinants measured included declarative knowledge of Planetary Health Diet composition, beliefs and self-efficacy. Dietary intakes of food groups were measured with a 37-item food frequency checklist, based on the Planetary Health Diet food groups. The World Index for Health and Sustainability (WISH) dietary score index was used to measure adherence to a healthy and sustainable diet.
Thirty-six participants completed the baseline survey. The sample was predominantly female (n=23), spoke English in their household (n=22), were employed (n=29) and were domestic students (n=22). The mean scores (out of 7) for all sustainable food literacy domains were high (self-perceived knowledge: 5.4±0.9; food skills: 6.0±0.6; attitudes: 5.3±1.0; action intent and strategies: 5.3±0.8). On the other hand, knowledge score for Planetary Health Diet composition was 5.8±1.8 out of 11 (53%). The majority of participants also reported that they were either ‘not confident at all' or only ‘somewhat confident’ in substituting meat for plant-based alternatives (n=24) and achieving protein requirements from plant-based options (n=26). Additionally, most participants disagreed that healthy and sustainable diets were convenient (n=24), affordable (n=19) and accessible (n=19). Total WISH score was 48.3±12.9 out of a maximum score of 130, indicating overall low adherence to healthy and sustainable diets.
This study underscores the need to improve adherence to healthy and sustainable diets in young adults. The results suggest that nutrition interventions should focus on improving declarative knowledge, beliefs and self-efficacy towards healthy and sustainable diets, rather than overall sustainable food literacy. Post-intervention and follow-up (four weeks after intervention) data will be available in September 2025, following the conclusion of the four-week intervention.