Levels of adherence to the Planetary Health Diet of current diets in Italian adults

Abstract Despite the efforts in the direction towards the identification of healthy and sustainable diets, little is known about the environmental impact associated with current diets. The aim of this study was to validate the application of the Planetary Health Diet Index (PHDI) to dietary habits currently adopted in a sample of adults living in southern Italy and background variables associated. Dietary intake from nearly 2000 individuals was assessed through a validated 110-item food frequency questionnaire. The PHDI was applied by considering the energy contribution of 16 different components with a gradual scoring system. For the estimation of the environmental impact, carbon and water footprint data for food commodities were extracted from the SU-EATABLE LIFE database and matched with the FFQ items. An energy-adjusted linear association between the PHDI scores and the majority of food groups included in the analysis was found; when considering the level of food processing, ultra-processed food consumption was inversely associated with PHDI scores. Among nutrients, PHDI scores were directly associated with fiber, antioxidant vitamins, potassium, plant-derived omega-3 poly-unsaturated fats, and inversely with sodium, total, saturated, mono- and poly-unsaturated fats, cholesterol, and protein. A significant difference in carbon and water footprint was observed across quartiles of PHDI scores as well as a linear direct association. After adjustment for potential confounding factors, 1-point increase in the PHDI score was associated with lower likelihood of being overweight or obese (OR = 0.99, 95% CI: 0.98-0.99). A linear inverse association between PHDI scores and waist and hip circumferences and, partially, with BMI but not with body weight was found. In conclusion, the PHDI seems to properly identify an environmentally friendly diet with a good nutritional quality. Key messages • An environmental-friendly dietary pattern resulted also having a good nutritional profile. • Adherence to the Planetary Health Diet is associated with parameters of central obesity.