Temporal Eating Patterns Show Inconsistent Associations With Cancer Incidence and Mortality: Systematic Review of Prospective Studies

Temporal eating patterns, such as eating time, frequency, and regularity, may be associated with cancer outcomes through circadian and metabolic pathways, but evidence remains limited.

We aimed to systematically review prospective studies examining associations between temporal eating patterns and cancer incidence or mortality.

Following PRISMA guidelines, PubMed and Embase were searched from inception to September 2, 2026. Eligible studies included prospective cohorts of adults assessing eating or fasting duration, nighttime eating, breakfast frequency or timing, meal regularity, or eating frequency in relation to cancer incidence or mortality. Meta-analyses were conducted when ≥3 studies examined comparable exposure-outcome pairs, and the quality of meta-evidence was evaluated using the NutriGrade scoring system. Risk of bias was assessed using the Risk of Bias for Nutrition Observational Studies tool.

Seventeen prospective cohort studies were included. Findings for eating or fasting duration and nighttime eating varied across studies for both cancer incidence and mortality. Lower breakfast frequency was associated with higher cancer mortality and colorectal cancer incidence in some studies, but not with breast cancer incidence. Greater eating-time variability and unrestrained eating were associated with higher cancer mortality, with unrestrained eating also associated with higher colorectal cancer incidence. Associations between eating frequency and cancer outcomes varied across studies and cancer sites. A meta-analysis of three studies showed a non-significant inverse association between eating frequency and colorectal cancer incidence in both categorical (HR = 0.81, 95% CI: 0.64-1.03) and dose-response analyses (HR per 1 time/day increase = 0.95, 95% CI: 0.89-1.01), with very low-quality meta-evidence. Risk of bias varied across domains, with common concerns related to confounding and exposure changes over follow-up.

Findings from cohort studies suggest potential associations between temporal eating patterns and cancer outcomes, but the evidence remains limited and heterogeneous, underscoring the need for further investigation.

CRD420251246423.