Open Access Publishing in Nutrition and Dietetics: State of the Art and Future Directions

Open science encompasses a set of practices designed to make the entire scientific research lifecycle and its outputs freely and openly accessible to all levels of society (David 2004; Suber 2012). This approach is widely recognised as a fundamental force for greater openness and collaboration within the scientific community (Fecher and Friesike 2014; Rentier 2019; Anagnostou et al. 2021; Maedche et al. 2024). Open Access (OA), data and methodology sharing and open peer review are core tenets of open science. They foster accountability and trust by allowing for independent verification and replication of studies. This transparency also promotes a more collaborative scientific environment, where researchers can build on each other's work more effectively and innovatively (Vicente-Saez and Martinez-Fuentes 2018). The removal of paywalls and subscription barriers, a key principle of OA, accelerates scientific progress by making research knowledge accessible to a broad audience, including researchers, educators, policymakers and the public. Open practices are especially critical for Nutrition and Dietetics (N&D) because the field is inherently linked to public health and individual well-being, making the accurate and timely dissemination of information essential. They ensure the latest evidence is readily accessible, verifiable, and usable by all stakeholders. Unrestricted access to peer-reviewed nutritional research directly enables health professionals—such as physicians, nutritional biologists and nutritionists/dietitians—to update their practices with the most current evidence, providing patients with accurate and timely nutritional information (Capocasa and Venier 2023). This ability to stay current is also a vital global health consideration, given that a poor diet remains a leading risk factor for mortality and morbidity worldwide (Chan et al. 2009; GBD 2017 Diet Collaborators 2019). Moreover, open science expedites the translation of research findings into clinical practice and public health policy (Spedding 2016), while also fostering innovation and strengthening collaborations with industry for the development of novel technologies and solutions (Friesike et al. 2015; Vicente-Saez et al. 2020). This facilitates the broader dissemination of scientific information into comprehensible content, supporting informed health decisions for the general public and ultimately promoting overall well-being. Recognising the paramount importance of open practices in N&D, we explored the evolving landscape of OA, drawing comparisons with trends observed in other health and life sciences disciplines. Our analysis of N&D publications indexed by Web of Science [see Capocasa et al. (2025) (data and Supporting Information file in Zenodo—link: https://doi.org/10.5281/zenodo.2599965)] reveals a consistent OA rise between 2000 and 2023 (Figure 1). The OA rate more than doubled, climbing from 31.4% in 2000–2003 to 62.9% in 2020–2023, with an average annual increase of 1.3%. Looking more closely at recent years (2020–2023), it is evident that OA rates for publications that are usually subjected to peer review—such as articles (63.9%) and reviews (60.8%)—are above or closer to the overall average OA rate of 62.9% (which refers to all N&D publications in the same period, including research articles, reviews, editorials, letters, book chapters and proceedings papers; see Capocasa et al. 2025). Conversely, editorials (59.8%) and letters (49.8%) remain below this average. These lower OA rates may be partly due to many subscription-based journals making this content freely available without an OA licence, which reduces the incentive for authors to pay for OA. In addition, universities and research institutions are increasingly prioritising the reimbursement of Article Processing Charges (APCs) for articles published in OA journals. They are more likely to support articles that demonstrate higher levels of scientific quality and prestige, such as research articles and reviews, criteria that are often associated with a greater number of citations (Björk and Solomon 2015). This disparity suggests the influence of funding mandates and institutional policies. Major funders, such as UK Research and Innovation (UKRI) and organisations participating in Plan S, explicitly require an OA licence for peer-reviewed outputs supported by their grants (Coalition S 2025; UK Research and Innovation 2023). Similarly, a growing number of university OA policies prioritise the deposit of final, revised manuscripts in institutional repositories (Harvard Library 2010; Oxford Brookes University 2025), further contributing to the observed trends. Beyond these policy-driven shifts, the COVID-19 pandemic also significantly impacted OA adoption (Lee and Haupt 2021; Riccaboni and Verginer 2022; Malkawi et al. 2023). The urgent global need for rapid knowledge sharing prompted publishers to waive APCs and funders to mandate OA for all COVID-19-related research, resulting in a notable surge in OA publications across diverse disciplines (Arrizabalaga et al. 2020; Capocasa et al. 2022; Sayer et al. 2023). Following the general trend, the OA rate of N&D was higher (an increase of 23.8%) than that of non-COVID-19 papers. However, the impact on overall OA rates was limited (+0.9%) due to the relatively low prevalence of COVID-19-related publications within our field (see Capocasa et al. 2025). As these policies have gained traction and evolved, the landscape of OA publishing has also shifted, leading to a preferred route for achieving OA. The Gold OA model—in which publishers make papers immediately and freely available, funded by APCs—has become the dominant route in scientific publishing, driven primarily by its immediate accessibility and alignment with funder and institutional mandates (Wang et al. 2018; Torres-Salinas et al. 2019). Alongside these advantages, a significant concern is the rise of predatory journals, which exploit APCs to publish articles without rigorous peer review (Shen and Björk 2015; Beall 2017). The surge in the OA model's popularity among authors stems from two main factors. As previously noted, many funding agencies and institutions now mandate OA publication, with grants often covering APCs to encourage authors to choose Gold OA (Mering 2020; Robinson-Garcia et al. 2020). This is further incentivised by the rise of transformative agreements, which are contracts between institutions and publishers that reallocate subscription fees to cover APCs, simplifying the OA transition and making it more attractive and accessible by reducing costs for individual researchers (Borrego et al. 2021; Moskovkin et al. 2022). Secondly, immediate OA significantly boosts research article visibility and impact, making content more discoverable and readable by a wider audience (Young and Brandes 2020). This increased exposure can lead to higher citation rates, a crucial metric for researchers and institutions (Lewis 2018; but see Langham-Putrow et al. 2021). Our analysis confirms a strong preference for the Gold OA route within N&D. Between 2020 and 2023, the majority of OA papers (86.4%) were published under a Creative Commons licence in either fully OA or hybrid journals, a trend that consistently increased throughout these 4 years (Figure 2). Notably, even within this dominant Gold OA trend, articles and reviews continue to lead the way (see Capocasa et al. 2025). Significantly, the Gold route has largely surpassed Bronze OA, where papers are readable but lack explicit reuse rights. However, the widespread adoption of Creative Commons licences brings with it a critical, yet often overlooked, issue: the complexity of these licences (Guibault 2008). Authors' limited understanding of the distinctions between licences and their impact on reuse and commercial rights can create hesitation. This knowledge gap is particularly critical in nutrition research, where the line between academic output and commercial application is often blurred. Conversely, we observed a decline in the Green OA road, where authors self-archive a version of a published manuscript, such as a pre-print or post-print, in an online institutional or disciplinary repository, showing again a consistent negative trend year by year (Figure 2). This OA model faces several challenges contributing to this outcome. For instance, embargo periods imposed by publishers reduce the immediate accessibility of research, potentially diminishing its impact both within and beyond academia (Koley and Lala 2022). Moreover, the existence of multiple article versions (pre-prints, post-prints) can lead to confusion regarding the authoritative version. Furthermore, complex and varied archiving policies create administrative burdens, sometimes making Green OA less appealing than Gold OA. Despite these challenges, Green OA remains a powerful and equitable option. It is a cost-effective pathway to meet OA mandates, particularly for researchers in low- and middle-income countries or those with limited institutional funds to cover APCs. Leveraging institutional and subject repositories is not just a secondary option, but a vital strategy to ensure that cost is never a barrier to knowledge sharing. Furthermore, Green OA can lead to citation rates at least comparable to those of Gold OA (Zhang and Watson 2017; Young and Brandes 2020), and if more fully leveraged without infringing publisher policies, it could significantly boost OA rates in biomedical research (Destro Bisol et al. 2022). How does N&D compare with other medical and biological fields in terms of OA rates? And what insights can we gain to identify facilitators and overcome barriers? A look at various disciplines reveals significant variation in OA rates, ranging from 42.5% in Anatomy and Morphology to 81.5% in Medicine, General and Internal (Figure 3). With N&D's OA rate (62.9%) falling slightly below the overall average (63.8%), it suggests this field has considerable potential for improvement. However, it is important to recognise that nutrition research often operates with more limited financial resources compared to other medical domains (Weaver and Miller 2017). Therefore, the APCs required by many Gold OA journals may slow the pace at which the field embraces broader OA adoption. In addition to this field-specific obstacle, a cultural barrier shared with other disciplines plays an important role. For many researchers, especially those in senior positions, the most prestigious and impactful work is still published in traditional, subscription-based journals like The New England Journal of Medicine and Nature. This creates a well documented ‘attitude–behaviour gap’ where their support for OA fails to translate into publishing behaviour (Köster et al. 2021). Senior researchers are often reluctant to publish their own high-impact work in OA journals for fear of it not being taken as seriously by promotion and tenure committees, a concern directly tied to how career advancement policies evaluate scholarly output (Pontika et al. 2022). Medicine, General & Internal, Medicine Research & Experimental, Oncology, and Genetics & Heredity stand out as fields with notably high OA rates, all exceeding 70%. Funder mandates probably play a pivotal role in elevating the adoption of OA in medical research. For instance, the National Institutes of Health (NIH), as the world's largest biomedical research agency, requires articles on biomedical and health topics funded by it to be submitted to its PubMed Central digital archive and made publicly accessible within 12 months of publication (National Institutes of Health 2025). Similarly, the Wellcome Trust and Cancer Research UK, leading global charitable foundations dedicated to improving health, require that all original published research they support—which heavily includes biomedical, clinical and genetics research—be made freely available from Europe PubMed Central upon publication, typically under a Creative Commons Attribution (CC BY) licence (Cancer Research UK 2022; Wellcome Trust 2025). While the influence of mandates on OA rates is well established, the exceptionally high OA rate observed in Genetics points to another powerful underlying force: its inherent research culture. This field frequently generates and analyses massive datasets, often millions or even billions of data points per individual. Openly sharing these vast datasets is a fundamental prerequisite for large-scale, publicly funded initiatives, and this practice is inextricably linked to publishing research OA. This is because these open research outputs significantly accelerate scientific discovery and foster international collaboration, both of which are essential for the advancement of genetics research. The Human Genome Project (HGP), completed in 2003, serves as a paradigmatic example. It allowed researchers worldwide to access, analyse, and build upon the data without delay, leading to a much faster pace of discovery than would have been possible under a more restrictive, proprietary model. Another important aspect that may help achieve higher OA rates is the availability of reputable OA. Currently, the fields of Medicine, General and Internal and Oncology have significantly more OA journals indexed by Web of Science compared to N&D; 47.7% (157 of 329) of Medicine, General and Internal journals and 34.3% (109 of 318) of Oncology journals are OA, while only 20.4% (31 of 109) of N&D journals are. This disparity suggests that the limited number of OA publication venues in N&D might be hindering its OA growth. The data presented effectively underscores the dynamic evolution of OA within N&D. The consistent rise in OA adoption through time mirrors the broader global shift towards open science, signalling positive progress for the field. However, our analysis also reveals that OA rate, despite its growth, still lags slightly behind leading medical fields. This gap presents a clear opportunity for improvement. To bridge this divide and further accelerate OA in N&D, the field can draw valuable lessons from the successful strategies observed in biomedicine. These include the implementation of stronger funder requirements, the provision of robust institutional support for OA costs, and the widespread adoption of the Gold OA model, often facilitated by transformative agreements, along with fostering the growth of reputable N&D-specific OA journals, mirroring trends in fields like Medicine, General and Internal, and Oncology (Severin et al. 2020; Borrego et al. 2021). Furthermore, while Gold OA has become the preferred route, often empowered by the diffusion of transformative agreements, it is crucial not to overlook Green OA. Actively encouraging Green OA for researchers facing financial constraints, along with optimising repositories for immediate, non-embargoed versions of articles, would significantly enhance accessibility and ensure that cost is not a barrier to open knowledge sharing. By embracing these multi-faceted approaches, N&D can fully leverage the benefits of OA, fostering greater research visibility, collaboration, and ultimately, scientific advancement. Beyond these specific strategies, a supportive research culture is essential for continuously advancing open science within the dynamic landscape of scholarly communication. This necessitates collaborative action among researchers, institutions, funders and publishers. Community-driven strategies, as advocated by Tennant et al. (2016), are crucial for fostering transparency and cooperation. To achieve this, in N&D and elsewhere, it is vital to integrate Open Science values and skills into academic training, starting with early-career researchers and PhD students. Educating the next generation of scientists on topics like open data sharing, open peer review, and the use of repositories is a key step in embedding these practices into the scientific process (Destro Bisol et al. 2014; Schönbrodt 2019). Furthermore, coordinated interdisciplinary efforts, bringing together nutritionists, clinicians, and data experts, can innovate to broaden research reach and impact. The Open Science Collaboration (Nosek et al. 2015), with its model for cross-disciplinary partnerships and guidelines for transparency, openness, and reproducibility, exemplifies how research culture drives open practices. This interdisciplinary approach in nutrition not only enriches scientific discourse but also highlights OA's vital role in fostering collaborations and improving public health outcomes (Capocasa and Venier 2023, 2024). In summary, N&D's journey towards open science reflects a promising commitment, yet the field has a clear path to further solidify its OA standing. By strategically adopting established best practices from leading biomedical disciplines, particularly regarding funder mandates and institutional support, N&D can boost its OA rates. Crucially, fostering a robust research culture that champions transparency and collaboration across disciplines, while also leveraging both Gold and Green OA pathways, will be key. While expanded access to scientific knowledge is vital for providing precise information, it also brings inherent risks. When research is made openly accessible to the broader public, including media professionals, journalists and policymakers, there is a risk of misinterpreting complex, subtle, or early-stage results. This challenge arises because even OA scholarly articles often contain specialised and technical terminology that is difficult for a general audience to understand. Moreover, the scientific community continues to face difficulties in conveying research findings clearly and impactfully to non-specialists. Such communication barriers can contribute to the spread of false information, as evidenced by the prevalence of fake news concerning nutrition online (Capocasa and Venier 2023). Addressing these challenges requires parallel efforts in effective science communication and media literacy initiatives, ensuring that OA translates into accurate understanding and informed decision-making. By combining robust OA practices with targeted communication strategies, N&D can maximise the benefits of open science—enhancing knowledge accessibility, driving scientific discovery, and contributing more broadly to global health improvements—while mitigating the risks of public misunderstanding. Conceptualisations: Marco Capocasa, Giovanni Destro Bisol and Davide Venier. Methodology: Marco Capocasa and Giovanni Destro Bisol. Writing original draft: Marco Capocasa, Giovanni Destro Bisol and Davide Venier. All authors have read and agreed on the manuscript content. This work was supported by the Istituto Italiano di Antropologia (www.isita-anthropology.com). G.D.B. was also supported by the National Recovery and Resilience Plan (NRRP) through the National Biodiversity Future Center. The authors have nothing to report. The authors declare no conflicts of interest. The data that supports the findings of this study are available in the Zenodo repository at the following link: https://doi.org/10.5281/zenodo.2599965.