Time-restricted eating (TRE) has gained popularity, but long-term data on its mortality effects has been lacking. A large-scale prospective cohort study of over 33,000 U.S. adults provides critical insight, revealing a distinct U-shaped relationship between the duration of one's daily eating window and all-cause mortality PMID:40944446. The data indicates a clear 'sweet spot' for longevity, with both extremely compressed and excessively long eating windows associated with a significantly higher risk of death. This finding moves the conversation from short-term biomarker changes to hard outcomes, providing an evidence-based target for optimizing meal timing. ### Key Findings Analysis of the NHANES 2003-2018 dataset, with a median follow-up of 8 years, identified a clear optimal eating duration associated with the lowest risk of death PMID:40944446. - **Optimal Window for Lowest Mortality:** The lowest risk for all-cause mortality was observed in individuals with an eating window of approximately **11-12 hours per day**. - **Risk of Short Windows:** An eating window of **8 hours or less** was associated with a **30% or greater increase in all-cause mortality** and a **greater than 50% increase in cardiovascular mortality** in older adults, men, and Caucasians. - **Risk of Long Windows:** An eating window of **15 hours or more** was associated with a **25% increase in all-cause mortality**. ### The Longevity Context This study's findings provide crucial long-term human data in the field of chrononutrition, an area where much of the evidence has come from smaller, short-term trials focused on metabolic markers rather than mortality PMID:40697195. The U-shaped curve identified is a common pattern in longevity science, where optimal health is found within a specific homeostatic range, and extremes in either direction are detrimental. A well-established parallel is seen with sleep duration, where a large meta-analysis also demonstrated a U-shaped association with mortality; the lowest risk was found at approximately 7 hours of sleep, with both shorter and longer durations linked to increased mortality PMID:28889101. These results are strongly corroborated by another recent, large-scale study using NHANES data which examined nighttime fasting duration—the inverse of the eating window PMID:38409117. That research found that a nighttime fast shorter than 10 hours or longer than 14 hours was associated with significantly greater cardiovascular and all-cause mortality. The optimal range identified in that study corresponds perfectly with the ~11-12 hour eating window pinpointed as ideal in the primary analysis, strengthening the conclusion that this moderate duration is a key factor in long-term health. ### Actionable Protocol Based on this robust observational evidence, individuals should aim to maintain a consistent daily eating window within the optimal range for longevity. 1. **Target a 10-12 Hour Eating Window:** Aim to consume all caloric food and beverages within a consistent 10 to 12-hour period each day. For example, if your first meal is at 8 AM, your last meal should be no later than 8 PM. 2. **Avoid Extremes:** Actively avoid both highly compressed (≤8 hours) and prolonged (≥15 hours) eating windows, as both are associated with increased mortality risk. 3. **Track for Consistency:** Use a simple method, like a notebook or a mobile app, to log the time of your first and last caloric intake for a few weeks to establish a consistent routine.