Introduction

Food systems encompass all elements and activities that relate to the production, processing, distribution, preparation, and consumption of food and the outputs of these activities, including socioeconomic and environmental outcomes [1,2]. Globally, current food systems have a considerable impact on the environment [3,4], causing environmental degradation and accelerated climate change, and often fail to adequately meet the nutritional needs of many regions [5,6].

In recent years, the relationship between diets and environmental sustainability has received increasing attention [6,7]. In 2023, the Stockholm Resilience Centre published an update on planetary boundaries highlighting that 6 of 9 boundaries were exceeded [8], with food systems being the main driver of excess for 5 of them [9]. In parallel, the Global Burden of Disease Study highlighted unhealthy dietary patterns lead to 11 million deaths and 255 million disability-adjusted life years annually [10,11]. These primarily stem from diet-related chronic diseases that also result in higher healthcare costs [12]. Indeed, globalization has contributed to a “nutritional transition” toward Western diets, characterized by high intakes of animal-sourced foods, refined sugar, processed foods and fats, and low intakes of fruits, vegetables, and whole grains [13]. The production of these foods is energy-intensive and relies heavily on nonrenewable inputs, contributing to environmental damage [[14], [15], [16]]. Food production processes account for over a third of global greenhouse gas emissions (GHGEs) [17,18]. As the world population is expected to increase from 8 billion currently to 10 billion around 2080 [19], global food production is anticipated to rise by 15% in the forthcoming decades, which may have an impact on food system GHGEs [20].

A crucial move toward more sustainable food systems is therefore needed. Several measures have been implemented to help develop guidelines and recommendations on what constitutes a healthy and sustainable diet [21]. The UN Sustainable Development Goals include goals for sustainable agriculture, consumption and production patterns, and combating climate change and its impacts [22]. In 2019, the FAO and the WHO jointly held a Consultation on Sustainable and Healthy Diets in Rome [21]. In the same year, The EAT-Lancet Commission report promoted universal nutrition guidelines, called the Planetary Health Diet. This report highlighted the importance of implementing a universal framework that each country can adapt to their national food-based dietary guidelines (FBDGs) [5]. The release of the EAT-Lancet report 2.0 in October 2025 highlighted the pivotal role of updating guidance on healthy and sustainable diets [9].

A key action to ensure healthy and sustainable diets are available, accessible, affordable, safe, and desirable is the creation of national FBDGs based on these principles (FAO/WHO) [23]. To achieve this, FBDGs are an essential public health tool to promote healthy diets and lifestyles for the general population and often form the basis of national nutrition policies. FBDGs include recommendations on foods, food groups, and dietary patterns based on scientific evidence while also taking cultural context into account [24]. Apart from influencing the food environment at a national level, FBDGs carry global repercussions, especially when recommending consumption patterns that may contradict the achievement of international environmental goals [25]. Therefore, they represent an opportunity to support the population in following sustainable and healthy diets [25,26].

As early as 2016, the FAO stated the importance of developing and disseminating FBDGs that stem from both health and sustainability objectives [27]. Shortly after, scientists concluded that future FBDG development should place greater emphasis on the environmental impacts of diets [24,28]. However, recent reviews have shown that most FBDGs continue to fall short of recommending reductions in the consumption of food groups associated with high GHGEs [29], and explicit guidance on environmentally sustainable dietary practices remains largely absent from consumer-facing materials [30].

Although most reviews have focused on consumer-facing FBDG documents, these represent only one stage of a broader evidence translation process in the development of FBDGs [31,32]. National FBDGs are typically developed through several layers of evidence, beginning with scientific or technical reports that synthesize the evidence base, which are then translated into guidance materials for health professionals and the public [31]. Sustainability considerations may therefore appear or disappear or be more explicitly articulated at different stages of this process.

Given the rapid pace at which FBDGs are being revised, it is essential to monitor their evolving content to identify emerging trends and assess progress toward the inclusion of sustainability principles. Building on these observations, the present study first aimed to examine the extent to which environmental sustainability messaging is incorporated into European FBDGs, using a structured set of sustainability criteria. A second objective was to evaluate the association between the presence of these messages in the FBDGs and the impact of these recommendations on recommended daily amounts of consumption for meat and legumes/pulses, considered as pivotal food groups in the shift toward more sustainable and healthy diets [5,33,34]. The analysis focused on FBDGs published in Europe, as this region has the highest number of countries with existing guidelines [35].