Temporal patterns of energy intake and cognitive function and its decline: a community-based cohort study in China

Dear Editor,
Worldwide, around 55 million people had prevalent dementia in 2019, which is expected to triple by 2050, especially in low- and middle-income countries. Lacking timely diagnosis and limited effective treatment for dementia make identifying risk factors crucial for its early prevention, among which dietary factors have received increasing attention.
Recently, accumulating evidence from population-based studies has linked the temporal patterns of energy intake (TPEI), usually defined as the temporal distribution of energy intake during a day, to mortality and metabolic diseases, such as diabetes and hypertension. In vitro and in vivo studies also revealed that meal timing could drive metabolic alterations and circadian regulation, and disrupted meal timing altered the peripheral circadian clocks in the hippocampus and consequently affected cognitive function. However, population-level evidence on the association between the TPEI and cognitive function remains lacking. We thus aimed to examine this relationship in the China Health and Nutrition Survey from 1997 to 2006, a community-based cohort study with national representativeness.
We included participants aged ≥55 years who completed at least one dietary assessment and cognitive test, and excluded those who: (1) had severe cognitive impairment at baseline (cognitive function score < 7/27); (2) had extreme energy intake (>99th percentile or <1st percentile); (3) had stroke, ischemic attack, hypertension, diabetes, or cancer at baseline. A total of 3342 individuals with up to four repeated measures over 10 years were included for analysis, the mean (standard deviation) baseline age of whom was 62.2 (6.8) years, 61.2% lived in rural areas, and 13.6% achieved a high school or higher degree…