This paper describes the first web-based self-completed 24-h recall designed to categorise food intake according to Nova groups – Nova24h – and its agreement with a reference tool in estimating the dietary relative contribution of the four Nova food groups (% of total energy intake).

Comparisons of estimates of dietary relative contributions of Nova groups obtained by Nova24h and one standard interviewer-led 24-h recall.

Nationwide adult cohort study in Brazil.

The subjects were 186 participants of the NutriNet Brasil Cohort Study (n 186).

No statistically significant differences were observed between the Nova24h and the reference tool mean contributions of unprocessed or minimally processed foods (52·3 % v. 52·6 %), processed culinary ingredients (11·6 % v. 11·9 %), processed foods (17·1 % v. 14·7 %) and ultra-processed foods (19·0 % v. 20·9 %). Intraclass correlation coefficients between individual estimates obtained for each Nova group showed moderate to good agreement (0·54–0·78). Substantial or almost perfect agreement between the tools was seen regarding the ability to rank participants according to quintiles of contribution of each Nova group (PABAK 0·69–0·81).

Nova24h is a suitable tool for estimating the dietary relative energy contribution of Nova food groups in the NutriNet Brasil cohort. New studies are necessary to verify its adequacy in other populations.