A data-driven trajectory analysis reveals associations between temporal patterns of within-day energy intake and...

Time-based diets are gaining popularity. However, their long-term health benefits remain unclear, primarily due to limited human data and the difficulty of sustaining them, as they often require strict eating schedules that may disrupt daily routines. To address these gaps, we used data-driven trajectory models to identify naturally occurring temporal patterns of within-day energy intake distribution and evaluate their associations with mortality risk.

We studied a nationally representative sample of 28,425 U.S. adults (age > 19 years) from NHANES (2005-2018). First, we calculated energy intake at 6 h intervals within a day using two 24 h food recalls per participants. Then, group-based trajectory analysis was performed, and four distinct temporal patterns of within-day energy intake were identified: "Skewed to Morning", "Skewed to Midday", "Skewed to Evening", and "Midday-evening Balance". All-cause and cause-specific mortality was ascertained through December 2019 using the National Death Index. Survey-weighted Cox proportional hazards regression was used to determine the association between daily energy intake trajectory groups and mortality, adjusting for sociodemographic, lifestyle, and amount and quality of dietary intake, BMI, sleep, health status, and recall days of the week.

Among participants, 17% had a Morning-skewed, 22% Midday-skewed, 22% Evening-skewed, and 39% Midday-evening Balanced intake pattern. Over a median 7.5 years follow-up, 2989 (7.6%) participants died. In unadjusted models, all skewed intake patterns were associated with higher all-cause mortality (p < 0.05). After adjustment, Morning-skewed (HR = 1.18, 95% CI 1.01-1.38) and Evening-skewed (HR = 1.23, 1.03-1.47) patterns remained associated with increased mortality risk, particularly among older adults, women, and White individuals.

Temporal patterns of energy intake skewed toward morning or evening were associated with increased mortality risk compared to a more balanced intake. These findings highlight the potential importance of temporal eating patterns in dietary recommendations. Further research is needed to confirm these relationships and explore underlying mechanisms.