A recent study explored this question in greater depth by examining whether meal timing and the length of our daily eating window are associated with mortality risk and life expectancy among U.S. adults.

Data tracking more than 30,000 adults age 40 and older revealed that when we eat our first and last meals may be linked to our risk of death and overall life expectancy. Starting the day with a later first meal was associated with a progressively higher risk of death from any cause and cardiovascular disease. People whose first meal was after noon had a 29% higher risk of death from any cause compared with those who ate their first meal between 7 and 8 a.m.

For the last meal, the lowest risk was observed around 7–8 p.m., and the highest risk was observed among those who ate past midnight.

The findings are published in the European Journal of Clinical Nutrition.

Meals on the clock

We have a decent understanding of the circadian rhythm—the body's internal clock, synced to the 24-hour cycle, that regulates not just sleep but essential biological functions, from hormone release to cellular repair. Scientists are now digging deeper into its links with food in a field of research called chrononutrition—the study of how meal timing interacts with our body's circadian rhythms to influence health, metabolism and weight regulation.