New study claims eating a late breakfast can reveal severe, life-threatening health problems

This is not an attack against intermittent fasters or people who get up early to facilitate direct sunlight into their eyeballs. There are many evolving strategies for maintaining or improving our individual health and lifespan. However, people's behaviors can also help doctors identify minor to severe medical issues that might seem like gimmick chasing, but actually reveal underlying health issues.

A 2025 study in Communications Medicine sought to understand meal timing in older adults. What they found was that as people age, their daily routines affect when they eat. The timing of their first meal of the day has a determining effect on when they eat later in the day. The shocking reveal: eating breakfast later was linked to a higher risk of death.

Man eats a simple breakfast.Image via Canva - Photo by DragonImages

Researchers use Chrononutrition to determine if you're healthy or not

Chrononutrition examines how the timing of our eating patterns affects our health. A 2024 study found, "The idea that 'when' we eat matters is grounded in circadian biology—the internal clock system that regulates various physiological processes over a 24-h cycle." Metabolic disorders, poor sleep quality, and cardiovascular issues can be linked to disruptions of this internal clock.

The lead author of the study, Hassan Dashti, a clinical nutrition scientist, in a 2025 article appearing in Medical News Today, said, “The timing of when we eat, known more commonly now as chrononutrition, has recently been recognized as an important factor that influences metabolism, sleep, and overall health."

So when we eat matters. And it's not necessarily because we choose to control our eating patterns; our actual health affects the reasoning for how we decide to navigate an eating schedule.

Young man puts his face on scrambled eggs. media2.giphy.com

A later breakfast is linked to several health issues

“The association between shifts toward later breakfast and higher mortality risk indicates that meal timing may reflect more than just personal preference and could be tied to biological aging or health decline,” Dashti said.

Researchers discovered that certain genetic profiles were linked to later meals. Meal time trajectories showed the difference between early and late breakfast eating groups, "... with 10-year survival rates of 86.7% in the late eating group compared to 89.5% in the early eating group."

Following nearly 3,000 older adults in the U.K. over several decades, researchers were able to gain a greater understanding of how individuals' meal times would change with age: "We found that as people aged, they tended to eat breakfast and dinner later, and those with more health problems or a genetic tendency to stay up late also tended to eat later."

The findings suggest that a later breakfast could serve as a marker for health in older adults and could be a guide for strategies in navigating healthy aging.

Health and late-night eating are linked

A 2023 study discussed synchronizing eating habits with the circadian rhythm, such as eating earlier in the day. It found that an early breakfast was generally associated with better glucose metabolism, less fat gain, and better cardiometabolic outcomes. People who ate later had poorer glucose tolerance and a higher body mass index.

A 2025 study on the risk of cancer and diabetes mortality showed a correlation to late-night eating patterns. The conclusion? "Night eating was associated with increased all-cause, cancer and diabetes mortality; however, reduction of excess mortality risk was observed when eating before 23:00 [11 pm] or low-dietary-energy-density foods."

Woman eats late night.Image via Canva - Photo by KoolShooters

These studies seem to suggest more relational than actual causal statistics. But doctors can recognize these patterns to explore possible issues. Eating later in the day could suggest underlying health issues worth investigating. In other words, just because you eat later doesn't mean you are actually at risk.