Timing of food intake, chrononutritional behavior patterns, and risk of metabolic syndrome in the French NutriNet-Santé cohort

Growing evidence from preclinical studies suggests that meal timing influences metabolic health. However, evidence in humans is inconclusive. This study aims to evaluate the associations between timing and frequency of food intake, energy distribution and chrononutritional behavior patterns, with metabolic syndrome (MetS) risk in a large cohort. We used dietary, lifestyle and sociodemographic, biological and clinical data from 16,436 adults (72% females, 51 years ± 13.7) from the NutriNet-Santé cohort, who attended a clinical visit (2011-2014). Associations between timing of first and last eating episodes of the day, number of eating occasions, nighttime fasting duration (NFD), eating jetlag, and percentage of energy intake after 5PM (from repeated 24-h records), and the risk of MetS, were evaluated using Poisson regression models, adjusted for key confounders. Chrononutritional behavior patterns were identified through PCA. All analyses were sex-stratified. At the clinical visit (after 2.1 years), 1,936 cases (11.8%) of MetS were identified. In fully adjusted models, in females, a later first eating occasion was associated with a higher risk of MetS (RR = 1.09 (1.02-1.16), P = 0.007). A prolonged NFD was associated with a higher risk of MetS, only when combined with a first eating occasion later than 8AM (RR = 1.11 (1.04-1.20), P = 0.002). In males, greater energy intake after 5PM (RR = 1.12 (1.04-1.20), P = 0.004), and a greater adherence to a pattern characterized by energy-rich first eating occasions (RR = 0.89 (0.84-0.95), P < 0.001) were associated with a lower risk of MetS. No associations were found between number of eating occasions or eating jetlag with MetS risk. This study highlights sex-specific associations between timing and distribution of food intake with MetS risk. These findings suggest that, beyond dietary quality, meal timing may serve as a complementary strategy for improving metabolic health and preventing MetS. Further longitudinal research is warranted.