For many years, the debate on sustainable diets remained largely confined to recommendations and good intentions: theoretically desirable models that proved difficult to translate into everyday, verifiable practices. OnFoods addressed this limitation directly by shifting the focus from prescription to experimentation, turning food sustainability into something measurable, testable, and validated in human studies.

Fully aligned with the theme of the “development and validation of new sustainable dietary models”, already outlined in the guidelines for system initiatives under Mission 4, Component 2 of the Italian National Recovery and Resilience Plan (PNRR), OnFoods moved research beyond the laboratory and into real-world contexts. By testing dietary models in practice, the project generated robust evidence on what it actually means to eat in a healthier and more sustainable way—and on how such choices can become realistically adoptable.

A major turning point was the systematic use of dietary intervention studies. In these studies, groups of volunteers follow defined and monitored dietary patterns so that their effects, adherence, and acceptability can be measured. This represents a crucial shift: moving from promising ideas—often derived from large observational datasets, where controlling all confounding variables is impossible—to validated models based on evidence collected under carefully controlled experimental conditions.

One example is the INSTEAD study, coordinated by the University of Milan, which validated through a randomized dietary intervention a customizable plant-based dietary model designed to be sustainable, nutritionally balanced, and feasible in everyday life.

The OBI WAN DIET project, led by the University of Parma, addressed a socially significant challenge: obesity prevention. Through a large-scale intervention—currently nearing completion—500 adults at cardiometabolic risk were involved in a study investigating how sustainable, polyphenol-rich, and personalized diets may support weight management and disease prevention.

ONMED, coordinated by the National Research Council (CNR) within Spoke 6, focused on an “innovated” Mediterranean model. Through a nutritional intervention, the project tested the effectiveness of a new version of the Mediterranean diet enriched with functional components, particularly in relation to gut microbiota health among adults at moderate to high risk of metabolic diseases.

The REFRAMED FOODS study, coordinated by the Council for Agricultural Research and Economics (CREA), implemented longitudinal interventions aimed at guiding people toward foods reformulated with lower salt and sugar content. These interventions were conducted in everyday settings such as canteens—including school canteens—and domestic consumption, marking an important step in demonstrating that sustainability can also be appealing and enjoyable.

Alongside dietary models, OnFoods has also validated a frequently overlooked idea: sustainability is closely linked to concrete choices along supply chains and in everyday consumption.

The TUNNEL study, for example, includes interventions based on meals or dietary patterns containing canned tuna, in order to assess real intake levels, eating behaviours, and nutritional indicators. This pragmatic approach integrates sustainability considerations with dietary preferences and nutritional quality.

Other projects have strengthened the methodological “toolbox” needed to make intervention studies comparable and reliable.

BRIDGE focuses on biomarkers and shared protocols to measure dietary adherence as well as nutrient and non-nutrient intake in a standardized way within intervention studies, increasing the robustness and comparability of results.

EDSUSDIETS uses university canteens as strategic environments for promoting healthy and sustainable diets, improving both food offerings and the decision-making environment. This approach can potentially reach thousands of people without requiring significant individual behavioural changes.

From a behavioural and psychological perspective, PSYFOOD investigates the facilitators and barriers—also emotional and cultural—that influence sustainable food choices. Its goal is to design targeted intervention protocols, recognizing that changing dietary habits is not only a matter of information, but also of motivations, perceptions, and social contexts.

• Explore the Research Projects section and search each project by its acronym

The quality of the results also stems from parallel work on technologies and products, aimed at making sustainable dietary models more accessible through reformulations, new ingredients, and cleaner production processes.

In particular, OnFoods’ approach to circularity has highlighted the importance of upcycling, recovering value from by-products and food waste. Valuable molecules—such as polyphenols, peptides, lipids, and other compounds relevant to consumer health—can be extracted and transformed into innovative ingredients and products, reducing waste while lowering environmental impacts.

• Several research projects focus on circularity, particularly within Spoke 2. Explore the dedicated section.

This link between what we should eat and what the food industry can sustainably produce makes the results especially strong, combining informed consumer choices, sustainable technologies, and evidence generated through human studies.

From a social perspective, the most important outcome of this approach has been to make the concept of a sustainable diet measurable and replicable. It is no longer simply a label, but a set of practices capable of improving both health and environmental outcomes while functioning in real-life settings—families, canteens, and populations facing specific risks or vulnerabilities.

From an economic perspective, a dual benefit can reasonably be expected. On one hand, new market opportunities may emerge (upcycled ingredients, reformulated foods, functional products), together with reduced costs linked to waste and inefficiencies. On the other hand, in the medium term, validated dietary models may contribute to lowering risk factors such as obesity, hypertension, and metabolic disorders, potentially reducing part of the healthcare burden.

Such impacts will require time to be fully quantified, but they are consistent with both the design of the studies conducted and the broader objectives of OnFoods.