Habitually Skipping Breakfast Is Associated with the Risk of Gastrointestinal Cancers: Evidence from the Kailuan Cohort Study

BACKGROUND: Habitually skipping breakfast may promote the initiation and progression of gastrointestinal (GI) cancers, which have never been systematically explored in large-scale prospective studies. METHODS: We prospectively examined the effects of breakfast frequency on the occurrence of GI cancers among 62,746 participants. The hazard ratios (HRs) and 95% confidence intervals (95% CIs) of GI cancers were calculated by Cox regression. The CAUSALMED procedure was used to perform the mediation analyses. RESULTS: During a median follow-up of 5.61 (5.18 ~ 6.08) years, 369 incident GI cancer cases were identified. Participants who consumed 1–2 times breakfasts per week exhibited an increased risk of stomach (HR = 3.45, 95% CI: 1.06–11.20) and liver cancer (HR = 3.42, 95% CI: 1.22–9.53). Participants who did not eat breakfast had an elevated risk of esophageal (HR = 2.72, 95% CI: 1.05–7.03), colorectal (HR = 2.32, 95% CI: 1.34–4.01), liver (HR = 2.41, 95% CI: 1.23–4.71), gallbladder, and extrahepatic bile duct cancer (HR = 5.43, 95% CI: 1.34–21.93). In the mediation effect analyses, BMI, CRP, and TyG (fasting triglyceride-glucose) index did not mediate the association between breakfast frequency and the risk of GI cancer incidence (all P for mediation effect > 0.05). CONCLUSIONS: Habitually skipping breakfast was associated with a greater risk of GI cancers including esophageal, gastric, colorectal, liver, gallbladder, and extrahepatic bile duct cancer. TRIAL REGISTRATION: Kailuan study, ChiCTR–TNRC–11001489. Registered 24 August, 2011-Retrospectively registered, http://www.chictr.org.cn/showprojen.aspx?proj=8050 SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11606-023-08094-7.