Breakfast has long been called “the most important meal of the day,” but researchers now suggest that when you eat it may be just as important as what you eat. In older adults, delayed meals often reflect health challenges such as fatigue, reduced appetite, or underlying conditions that interfere with normal routines. According to Dr. Hassan Dashti, a nutrition scientist and circadian biologist at Massachusetts General Hospital and Harvard Medical School, mismatched eating schedules can disrupt the body’s natural rhythms.

“When food arrives at a time the body doesn’t expect, like late at night or much later in the morning, it can disturb sleep, metabolism, and other biological processes,” Dr. Dashti explained. “For younger adults, these disruptions may have a smaller effect, but for older adults, they can translate into a meaningful health burden.”

Inside the Study: 22 Years of Data

The research, published in Communications Medicine, analyzed nearly 3,000 older adults in the UK, tracked for an average of 22 years. Participants, who entered the study around age 64, regularly reported their eating schedules, lifestyle habits, and health conditions between 1983 and 2017.

Some participants also underwent genetic testing, allowing researchers to explore links between meal timing and traits such as “eveningness” (a natural tendency to prefer late nights) and obesity risk. They also completed questionnaires about sleep quality and underwent repeated assessments of physical and psychological health.

The results were striking:

• Later breakfast times were strongly linked to both physical and psychological illnesses such as fatigue, poor oral health, depression, anxiety, and multiple chronic conditions.
• Mortality risk was higher among participants who consistently ate breakfast later in the day.
• A survival analysis showed a clear gap: 10-year survival rates were 89.5% in the early breakfast group versus 86.7% in the late group.

While the percentage difference may appear small, researchers stress that it represents a meaningful population-level effect, especially given the large sample size and long follow-up.

What the Findings Really Mean

Importantly, the researchers clarified that the results do not prove eating later causes death directly. Instead, a delayed breakfast may serve as an early warning sign of broader health decline. Older adults may eat later because of low energy, poor appetite, or other medical conditions, making breakfast timing a sensitive indicator of overall health.

Interestingly, genetic profiles tied to eveningness — but not obesity — were associated with later meal schedules. This suggests that while natural “night owl” tendencies can play a role, environmental and health-related factors are likely the bigger drivers in older adults.

Practical Takeaways: Consistency Is Key

Dr. Dashti and colleagues emphasize one main message: consistency matters. For older adults, maintaining a regular meal schedule with an earlier breakfast may support better metabolic health, stronger circadian alignment, and healthier aging.

They recommend:

• Avoiding skipped or heavily delayed breakfasts unless guided by a physician
• Monitoring appetite changes or unexpected weight loss, as these may flag underlying health problems
• Encouraging earlier meal times where possible, especially for breakfast, to better align with the body’s internal clock

Monica Dinu, PhD, a nutrition expert from the University of Florence, praised the study, noting that it adds to evidence showing the benefits of aligning meals with circadian preferences. She suggested that healthcare providers should pay closer attention to meal timing in older adults, not just diet quality.

The Bottom Line

The study doesn’t mean that one late breakfast will harm you, but it underscores a powerful truth: in later life, when you eat could be as critical as what you eat. For older adults, an early, consistent breakfast may serve as a simple yet powerful tool to support longer, healthier living.