Exploring ultra-processed food consumption: adherence to food-based dietary guidelines, nutrient intake and the associated greenhouse gas emissions in Iceland

Ultra-processed foods (UPF) are often energy dense and low in nutrients. High consumption of UPF has been associated with non-communicable diseases, premature mortality and environmental impacts. The objective of this study was to assess UPF consumption in relation to diet quality and associated greenhouse gas (GHG) emissions, previously not examined in Iceland. Data from the Icelandic National Dietary Survey (2019–2021, <i>n</i> 822) were utilised. The NOVA classification system was used classifying all food and drinks reported. Dietary GHG emissions were quantified using an open-source life cycle assessment database. On average, 45 %±15 of the total calories consumed daily were derived from UPF, ranging from 24 % in the lowest quartile (UPFQ1) to 64 % in the highest quartile (UPFQ4). The energy contribution of UPF considered to fall within the Icelandic dietary guidelines was 4 %±4. UPFQ4 had significantly lower consumption of, e.g. red meat, fruits, vegetables and whole grains and higher consumption of, e.g. refined grains, sweets and soft drinks, compared with UPFQ1. UPFQ4 had a significantly higher energy intake, added sugar intake and lower intake of, e.g. proteins and iodine. The median (interquartile range (IQR)) share of dietary GHG emissions was 21 % (IQR: 11–34) of total kg CO₂-eq/d, while significantly lower in UPFQ4 compared with UPFQ1. Almost half of the daily energy intake of Icelandic diets was derived from UPF, reflecting relatively poor diet quality. However, dietary GHG emissions were relatively low in high consumers of UPF, reflecting higher meat consumption in low consumers of UPF. Findings underline the urgency of policy implementation, aligning food consumption with dietary guidelines.