Carbon Footprint of Childhood Diets-A Secondary Analysis of Population-Based Studies

Food-based dietary guidelines (FBDG) aim to support health and reduce the environmental impacts, including the dietary carbon footprint (CF). Children's dietary CF is largely unknown.

The aim of this study was to estimate the CF of children's diets, identify the main food groups contributing to CF across different age groups, and to assess how adherence to FBDG might influence CF.

The study included participants in 5 age groups (3, 5, 6, 9, and 15 y; N = 943) randomly selected from the capital area or nationwide during 2003-2012 in Iceland. Dietary intake was assessed using 3-d food records for 3-, 5-, and 6-y-olds and two 24-h recalls for 9- and 15-y-olds. Dietary CF was estimated using life cycle assessment data from the Danish CONCITO Big Climate Database. To assess how adherence to the Nordic FBDG alters dietary CF, comparison with the CF of recommended amounts of food groups, adjusted to children, was done.

Mean total dietary CF (kg CO₂-eq/d) was 2.9-3.2 for 3-, 5-, and 6-y-olds and 4.1 for 9-y-olds; among 15-y-olds, it was 4.4 and 5.4 for girls and boys, respectively. Meat was the main contributor to CF across all age groups, followed by dairy products. Discretionary foods (e.g., sweets, snacks, and soft drinks) ranked third among 6-, 9-, and 15-y-olds. Fruits and vegetables contributed little to CF, as did fish, except in the 2 youngest age groups. Comparison with FBDG estimated for children showed that a closer adherence to FBDG would decrease CF.

Meat and dairy were the largest contributors to dietary CF, with discretionary foods ranking third among children aged ≥6 y upward. The results highlight the potential positive climate impact of transitioning toward more plant-based diets and adhering to the FBDG.