Identifying sustainable foods from among those culturally acceptable by Portuguese children and adolescents (3–17 years old)

Promoting sustainable diets requires identifying those foods that balance nutritional quality, environmental impact, and cost, and taking cultural preferences into account. However, research on the sustainability of dietary habits in non-adult populations are limited. This cross-sectional study aims to investigate the relationship between different sustainability indicators and identify sustainable foods among those culturally acceptable by Portuguese children and adolescents. Dietary intake of 521 children and 633 adolescents was determined using food-diaries and 24-h recalls, respectively. Nutritional, environmental, and economic indicators were assessed for each food item identified as culturally acceptable among Portuguese children and adolescents. Spearman correlations were computed to assess the relationship between sustainability indicators. A sustainability score (0–3) was calculated to identify the most sustainable foods. Nutritional quality was positively correlated with greenhouse gas emissions and cost and inversely correlated with food industrial processing. Only around 10% of foods received a maximum sustainability score, namely fresh and processed vegetables, fresh fruit and fruit jars, legumes, pasta, rice and other grains, potatoes and other starchy tubers, natural and 100% fruit juices, and nectars. Overall, the most nutritious foods tend to have a higher environmental impact and cost, and few food options are simultaneously nutrient-rich, environmentally friendly and affordable.