Assessment of the Sustainability of the Mediterranean Diet Combined with Organic Food Consumption: An Individual Behaviour Approach

Mediterranean diets are promising sustainable food models and the organic food system may provide health and environmental benefits. Combining the two models could therefore be a favourable approach for food sustainability. The aim of this study was to draw up a comparative description of four diets differing in the level of organic foods consumption and the adherence to the Mediterranean diet, using multidisciplinary indicators to assess the sustainability of these diets. Four groups of participants were defined and compared, combining the proportion of organic food in their diet (Org versus Conv) and the adherence to the Mediterranean diet (Med versus NoMed). Conv–NoMed: Conventional consumers and non-Mediterranean diet followers; Conv–Med: Conventional consumers and Mediterranean diet followers; Org–NoMed: Organic consumers and non-Mediterranean diet followers; Org–Med: Organic consumers and Mediterranean diet followers. The adherence to nutritional recommendations was higher among the Org–Med and Conv–Med groups compared to the Conv–NoMed group (using the mPNNS-GS (modified-Programme National nutrition santé guidelines score/13.5 points): 9.29 (95% confidence intervals (CI) = 9.23–9.36) and 9.30 (95% CI = 9.24–9.35) versus 8.19 (95% CI = 8.17–8.22)) respectively. The mean plant/animal protein intake ratio was 1.38 (95% CI = 1.01–1.74) for the Org–Med group versus 0.44 (95% CI = 0.28–0.60) for the Conv–NoMed group. The average cost of the diet of Org–Med participants was the highest: 11.43 €/day (95% CI = 11.34–11.52). This study highlighted the importance of promoting the Mediterranean diet combined with organic food consumption for individual health and environmental aspects but challenges with regard to the cost remain.