This study aims to investigate the relationship between breakfast consumption behavior and cognitive function in Chinese adults aged 55 years and above, and the mediating effect of diet quality.

Data were drawn from the China Health and Nutrition Survey (CHNS) 1997, 2000, 2004, 2006, 2015, and 2018. Participants aged 55 years and above who had at least two waves of completed data on dietary measures and cognitive assessments were eligible. Breakfast consumption behavior was counted during the 3-day 24-h survey period and classified into breakfast skipping and breakfast consumption. Cognitive function was examined using part items of the Telephone Interview for Cognitive Status-modified. Three-level linear mixed-effects models were performed to examine the relationship between breakfast consumption behavior and cognitive function due to the repeated-measured data. The Mediating effect of diet quality, indicated by the China Elderly Dietary Guidelines Index 2022 (CDGI 2022-E), was explored.

A total of 5462 participants were included. Significant associations between breakfast consumption behavior and global cognitive score (breakfast skipping vs. consumption: β = −0.77, 95%CI: −1.23, −0.31) as well as global cognitive composite z-score (breakfast skipping vs. consumption: β = −0.22, 95%CI: −0.30, −0.15) were observed in total participants. Similar significant associations were found in participants stratified by age at baseline or gender. Overall diet quality assessed by CDGI 2022-E played a modest mediating role between breakfast consumption behavior and cognitive score.

Habitual breakfast consumption may have the advantage of improving cognitive function in the Chinese older population, in which overall diet quality exerted a mediating effect.