Introduction: A gluten-free diet (GFD) remains the only effective treatment for coeliac disease, requiring complete exclusion of gluten-containing cereals and the use of naturally gluten-free foods or specific substitutes. However, the environmental sustainability of GFD-based food choices has been questioned.
Methods: A retrospective analysis of food diaries from 81 participants (44 coeliac and 37 non-coeliac subjects) was conducted to evaluate environmental impact and adherence to Mediterranean Diet guidelines. Weekly quantities and consumption frequencies of all foods and beverages were assessed. Water footprint and CO₂ emissions of each food item were estimated using the SU-EATABLE LIFE database. Mediterranean Diet adherence was evaluated by comparing weekly intake frequencies across food groups.
Results: Total macronutrient intake did not differ significantly between groups. However, coeliac patients showed a significantly higher environmental burden, with increased mean weekly water footprint (17,274 vs 14,442 litres, p < 0.01) and carbon footprint (19.5 vs 15.7 kg CO₂-eq/week, p < 0.01). This difference was mainly driven by greater consumption of rice- and corn-based substitutes, along with higher intake of fresh fruit and gluten-free snacks. Overall Mediterranean Diet adherence was acceptable in both groups, though coeliac patients showed lower adherence for aged cheeses.
Conclusion: Although clinically essential, GFD is associated with greater environmental impact. Supporting coeliac patients in selecting more sustainable gluten-free options represents an emerging nutritional and environmental challenge.