Examining the relationship between the environmental impact of diet and child growth from a co-benefit perspective.

The adoption of diets that minimize both their environmental impacts and weight excess in children would be a major co-benefit for climate change mitigation. We evaluated the relationship between child diet-related environmental impact and anthropometric characteristics in an Italian birth cohort. The study involved 2127 children of the Piccolipiù birth cohort. At 4 years, their diet in the previous two months was assessed through a questionnaire, from which we derived individual: (i) diet-related daily greenhouse gas emissions (GHGE), (ii) land use (LU), (iii) adherence to the Mediterranean Diet (MD) and (iv) red meat consumption. We related these variables with overweight and obesity, waist circumference, and height at 4 years using regression models adjusted for a priori selected confounders. Diet-related GHGE and LU had a positive weak association with overweight and obesity, with an odds ratio (OR) for the fourth vs. second quartile of 1.30 for both GHGE (95% confidence intervals -CI-: 0.96; 1.77) and LU (95% CI: 0.96-1.76). Both OR estimates increased after adjustment for energy intake. GHGE and LU were not associated with height, with the exception of shorter children in the first quartile. A high vs. low MD adherence was associated with an increase in height Z-score of 0.11 (95% CI 0.01; 0.21). No association was found for red meat consumption. These results suggest that lowering the impact of high environmental impact diets may have, if anything, beneficial effects on child obesity, overweight, and height, with pro-MD patterns playing an important role.