To identify ultra-processed foods (UPF) contribution to daily energy and nutrient intake in Iranians and examine whether UPF intake is associated with nutrient profile and diet quality.

In this cross-sectional study, a validated FFQ was used to evaluate usual dietary intake over the preceding year. NOVA system was applied to categorise foods based on their levels of processing. Diet quality was evaluated using the nutrient adequacy ratio (NAR), Nutrient Rich Food Index (NRF) and hybrid nutrient density.

The LIPOKAP study conducted in five cities of Iran (Isfahan, Birjand, Bandar Abbas, Kermanshah and Shahrekord).

A total of 1994 adults aged ≥18 years were recruited using stratified multistage random cluster sampling method.

UPF were responsible for 8·5 % of daily energy intake. In the adjusted model, UPF consumption was inversely associated with carbohydrate, protein, refined and whole grains, fibre, fruit and meat, but was positively linked to energy, total fat, saturated and trans fatty acids and cholesterol. Compared with those in the lowest tertile, individuals in the highest tertile of UPF had smaller NAR for Ca, Mg, Zn, Fe, phosphorus, thiamin, niacin, folate and vitamin C. Both NRF and hybrid nutrient density decreased when the share of daily energy intake from UPF increased.

The higher consumption of UPF is associated with poorer diet quality and lower nutrient intake. It is recommended that UPF be replaced with minimally processed foods to improve diet quality and nutrient profile.