PROMOTION OF PLANT-BASED SUSTAINABLE DIETARY PATTERNS FOR THE ITALIAN POPULATION: FROM FEASIBILITY TO THE IMPACT ON NUTRITIONAL STATUS AND HEALTH-RELATED MARKERS

The growing awareness of the environmental impact of food systems has intensified the focus on sustainable, healthy diets. Transitioning to dietary patterns with lower environmental impacts is essential for reducing greenhouse gas emissions and conserving natural resources, aligning with broader public health goals. Moreover, high-income populations, in particular, face high rates of chronic non-communicable diseases linked to their diets and lifestyles. In this context, the FAO defined sustainable healthy diets in 2010 as those that support human health, minimize environmental impacts, and are both affordable and culturally acceptable. Therefore, the acceptability of sustainable dietary patterns is crucial. This thesis contributes to the study of the complex relationship between dietary habits, lifestyle, and their effects on human and planetary health, emphasizing the importance of diet and lifestyle in maintaining well-being. Firstly, despite ongoing debates about the definition of sustainable healthy diets, adopting plant-based diets with higher consumption of plant-based foods remains a viable option. These diets are rich in essential nutrients, including dietary fibers, which offer significant health benefits both directly and possibly mediated by the modulation of microbial ecosystem. For this reason, a review on the impact of dietary fibers on gut microbiota and short-chain fatty acid production in healthy adults has been performed. Secondly, a pilot intervention study assessed the metabolic and functional effects of an Italian-Mediterranean plant-based diet, the EAT-IT dietary pattern, on various health-related biomarkers to evaluate its nutritional adequacy. This study also highlighted important factors affecting diets acceptability. The findings enabled the optimization of the MED_EAT-IT dietary pattern. A subsequent larger dietary intervention provided insights into the health benefits and acceptability of plant-based diets. Moreover, an in-depth analysis of volunteers' lifestyle and physical fitness has been performed. Lastly, thanks to the collaboration with the University of Madrid, the importance of physical fitness was explored as a further marker to be considered for the evaluation of the impact of sustainable diets and also the adherence to the Planetary Health Diet among Spanish adults with adverse food reactions. This latter aspect is crucial as it addresses the need for tailored recommendations for specific populations to facilitate the adoption of healthy and sustainable diets. In conclusion, this thesis aimed to contribute to the challenges associated with the promotion of sustainable healthy diets, providing further valuable data on their impact on health outcomes also addressing behavioural and environmental considerations.