Night eating in timing, frequency, and food quality and risks of all-cause, cancer, and diabetes mortality: findings from national health and nutrition examination survey

Objective: To investigate the association of timing, frequency, and food quality of night eating with all-cause, cancer, and diabetes mortality. Methods: This study included 41,744 US adults from NHANES 2002–2018. Night eating was assessed by 24-h dietary recall; exposures were timing, frequency, and food quality (derived via latent class analysis). Outcomes were all-cause, cancer, and diabetes mortality identified via the National Death Index and ICD-10. Adjusted hazard ratios (aHR) with 95% confidence intervals (CI) were estimated by Cox regression. Results: Over a median 8.7 years, 6066 deaths occurred (1381 cancer, 206 diabetes). Later night eating was associated with higher all-cause and diabetes mortality (each P-trend <0.05) but not cancer mortality overall; highest risks were at 00:00–1:00 for all-cause (aHR 1.38, 95% CI 1.02–1.88) and 23:00–00:00 for diabetes (aHR 2.31, 95% CI 1.21–4.40); 22:00–23:00 showed no increased all-cause risk. Night eating once or ≥2 times was associated with higher all-cause and diabetes mortality (each P<0.05). Elevated risks were observed in the high dietary energy density night-eating group (all-cause aHR 1.21 [95% CI 1.06–1.38]; diabetes aHR 1.97 [95% CI 1.13–3.45]) but not in the low-density group. Night eating correlated positively with glycohemoglobin, fasting glucose, and OGTT. Conclusions: Night eating was associated with increased all-cause, cancer, and diabetes mortality; reduced excess risk was observed when eating before 23:00 or consuming low–dietary-energy-density foods.