Assessing Gender and Age Differences in the Adoption of Sustainable Diets: Insights from an Intervention of the Mediterranean Diet

Introduction: Sustainable nutrition is integral to environmental health and con- servation. Gender and age differences influence dietary patterns, but their impact on the adoption of sustainable diets remains unclear. This study investigates the effects of a Mediterranean diet intervention on diet sustainability, focusing on gender and age differ- ences. Methods: A cross-sectional study was conducted on 1666 participants (58.2% women) aged 18–75 years. Dietary preferences were assessed through food diaries and sustainability indices before and after the intervention. Participants followed a low-calorie Mediterranean diet for two months, with food diaries tracking their weekly consumption. Changes in sustainable and non-sustainable food consumption were analysed using paired t-tests and stratified by gender and age groups. Results: Men consumed significantly more meat and processed meat (p < 0.001), while women preferred low-fat yoghurt and whole grains (p < 0.01). Despite an increase in legume consumption (3.2%, p < 0.001), the overall sus- tainability index decreased due to a compensatory rise in meat consumption among men (p < 0.001), particularly in younger (<30) and older (>50) participants. Gender-related differences were observed, with female participants reporting a higher intake of foods classified as sustainable. However, significant cultural and palatability barriers limited the uptake of some sustainable foods such as tofu. Discussion: The intervention highlighted the challenges in promoting sustainable eating habits. Gender-targeted and age-specific strategies are critical to overcome barriers and support dietary improvements. Future interventions should incorporate cultural preferences and provide long-term support to achieve significant changes in behaviour. Conclusions: The Mediterranean diet interven- tion, conducted within an Italian cohort, highlighted both opportunities and challenges in promoting sustainable dietary transitions. Tailor-made approaches are essential to meet the different needs of various demographic groups. However, the effectiveness of nutrition programmes focusing on sustainabili