AbstractThis study aims to investigate the dietary share of ultra-processed foods and its association with the non-communicable disease (NCD)-related nutrient profile of adult and elderly populations in Portugal. Cross-sectional data from the National Food, Nutrition and Physical Activity Survey (2015–2016) of the Portuguese population were analysed. Dietary intake was assessed by two non-consecutive 24-h recalls, and food items were classified according to the NOVA system. We estimated the percentage of dietary energy provided by each of the NOVA food groups and assessed the NCD-related nutrient profile of the overall diet across quintiles of ultra-processed food consumption. Weighted t tests, besides crude and adjusted linear and Poisson regressions, were performed. Ultra-processed foods contributed to around 24 and 16 % of daily energy intake for adults and elderly, respectively. In both groups, as the consumption of ultra-processed foods increased, the dietary content of free sugars, total fats and saturated fats increased, while the dietary content of protein decreased. In adults, total energy intake, dietary energy density and content of carbohydrates also increased as the consumption of ultra-processed foods increased, while the dietary content of fibre, Na and K decreased. The prevalence of those exceeding the upper limits recommended for free sugars and saturated fats increased by 544 and 153 % in adults and 619 and 60 % in elderly, when comparing the lowest with the highest quintile of ultra-processed food consumption. Such a scenario demands for effective strategies addressing food processing in the Portuguese population to improve their diet quality and prevention against diet-related NCD.