Introduction:
Incorporating sustainability into nursing education is crucial to prepare future professionals to address global health challenges. While lecture-based learning (LBL) remains predominant, problem-based learning (PBL) offers student-centred approaches that may enhance understanding and engagement with topics like sustainable nutrition. This study assessed the impact of PBL versus LBL on nursing students' knowledge and perceptions of healthy and sustainable nutrition.

Methodology:
A quasi-experimental study was conducted in the 2023/24 academic year with second-year nursing students from the University of the Basque Country UPV/EHU (Spain). Of 104 eligible to participate, 72 completed pre- and post-tests. Participants were divided into PBL (n=36) and age- and sex-matched LBL (n=36). Both methods were applied over six sessions (April-May 2023) by the same instructor, focused on dietary recommendations and sustainability. PBL employed active learning techniques (mind mapping, jigsaw puzzle, 1-2-4 technique and poster presentation); while LBL relied on traditional lectures. Data were collected using a validated-survey on knowledge and perceptions of food sustainability that used a 5-point Likert scale response option [1]. Ethical approval was obtained from the Ethics Committee of the UPV/EHU. Statistical analyses involved t-tests and mixed-design ANOVA, with p<0.05 considered significant.

Results:
Socio-economic profiles of the two groups were similar. Pre-intervention, awareness of sustainability concepts was limited (e.g., 15.3% had never or hardly ever heard about food's environmental impact, 31.9% were unfamiliar with the UN's SDGs, and 77.8% of the European Green Deal). Post-intervention, all participants reported familiarity with these concepts. Most concerning aspects regarding healthy and sustainable nutrition pre-intervention were hygiene at home and outside (3.8±1.0), food waste (3.6±1.2), and contamination by viruses and bacteria (3.5±1.2). No significant differences were observed in concern levels between the groups in the pre-test. Post-intervention, concern levels increased in significantly in areas like sugar and salt content (from 3.1±1.2 to 4.1±1.0, F=33.956; p<0.001), followed by animal welfare (from 2.7±1.2 to 3.5±1.1) (F=24.404; p<0.001) and antibiotic and hormone residues in animal products (from 2.5±1.4 to 3.1± 1.1) (F=19.952; p<0.001). The PBL group showed greater increases in concern for animal welfare (F=4.368; p=0.040) and plastic use (F=4.126; p=0.046) than LBL.

Conclusions:
Both PBL and LBL effectively improved students' knowledge and perceptions of healthy and sustainable nutrition. However, PBL demonstrated additional benefits by fostering greater concern for critical sustainability issues, highlighting its potential as a transformative teaching approach in nursing education. Further research should evaluate PBL's long-term impact on professional practice and its broader applicability within the curriculum, by conducting larger follow-up interventions.
Acknowledgements: Supported by the Vice-Rectorate for Undergraduate and Educational Innovation UPV/EHU (code: i324-01).

References:
[1] M.C.M.P. Gaspar, R. Celorio-Sardà, O. Comas-Basté, M.L. Latorre-Moratalla, M. Aguilera, G.A. Llorente-Cabrera, M. Puig-Llobet and M.C. Vidal-Carou, “Knowledge and perceptions of food sustainability in a Spanish university population”. Front Nutr, vol.9, 2022. doi:10.3389/fnut.2022.970923

Keywords: Problem-based learning, Lecture-based learning, Nursing education, Healthy and sustainable nutrition.