Carbon dioxide (CO 2 ) emissions and adherence to Mediterranean diet in an adult population: the Mediterranean diet index as a pollution level index.

Background: Research related to sustainable diets is is highly relevant to provide better understanding of the impact of dietary intake on the health and the environment.
Aim: To assess the association between the adherence to an energy-restricted Mediterranean diet and the amount of CO ₂ emitted in an older adult population.
Design and Population: Using a cross-sectional design, the association between the adherence to an energy-reduced Mediterranean Diet (erMedDiet) score and dietary CO ₂ emissions in 6646 participants was assessed.
Methods: Food intake and adherence to the erMedDiet was assessed using validated food frequency questionnaire and 17-item Mediterranean questionnaire. Sociodemographic characteristics were documented. Environmental impact was calculated through greenhouse gas emissions estimations, specifically CO ₂ emissions of each participant diet per day, using a European database. Participants were distributed in quartiles according to their estimated CO ₂ emissions expressed in kg/day: Q1 (≤2.01 kg CO ₂ ), Q2 (2.02-2.34 kg CO ₂ ), Q3 (2.35-2.79 kg CO ₂ ) and Q4 (≥2.80 kg CO ₂ ).
Results: More men than women induced higher dietary levels of CO ₂ emissions. Participants reporting higher consumption of vegetables, fruits, legumes, nuts, whole cereals, preferring white meat, and having less consumption of red meat were mostly emitting less kg of CO ₂ through diet. Participants with higher adherence to the Mediterranean Diet showed lower odds for dietary CO ₂ emissions: Q2 (OR 0.87; 95%CI: 0.76-1.00), Q3 (OR 0.69; 95%CI: 0.69-0.79) and Q4 (OR 0.48; 95%CI: 0.42-0.55) vs Q1 (reference).
Conclusions: The Mediterranean diet can be environmentally protective since the higher the adherence to the Mediterranean diet, the lower total dietary CO ₂ emissions. Mediterranean Diet index may be used as a pollution level index.
(© 2023. The Author(s).)