How and when we eat as we get older changes, but what impact this has on our health isn't well understood. New research, however, has found that in midlife and beyond, eating one particular meal later in the day is linked with a higher risk of early death.
Thanks to one of the most successful marketing campaigns of the 21st century, as well as a post-war shift in the workforce, generations have grown up hearing that "breakfast is the most important meal of the day." And while the data on this remains inconclusive, much of the research has so far focused on children or younger adults.
In a new study, Mass General Brigham researchers turned their attention to older adults – midlife and beyond – to better understand if eating schedules are tied to age-related health problems. This demographic has been largely overlooked when it comes to the science of chrononutrition – when we eat.
“Up until now, we had a limited insight into how the timing of meals evolves later in life and how this shift relates to overall health and longevity,” says lead author Hassan Dashti, PhD, a nutrition scientist and circadian biologist at Massachusetts General Hospital.
The researchers looked at the data, including blood records, of 2,945 community-dwelling adults aged 42–94 years, who each had up to five assessments regarding meal timing and health between 1983 and 2017. Those assessments gathered detailed information about each individual, including health status, lifestyle behaviors, weight, sleep quality and time spent preparing meals.
What they found was that, for many reasons – from physical disability to oral hygiene – older adults generally ate breakfast later, had a later eating midpoint in the day and had a shorter eating window overall.
"Later breakfast timing is associated with greater physical and psychological illness, multimorbidity, evening chronotype genetic profiles, and increased mortality risk," the researchers noted. "These findings suggest that shifts in meal timing may reflect underlying health and aging processes in older adults."
Through complex modeling that is detailed in the Nature paper, the researchers found that later breakfast timing was linked with an increased risk of death during follow-up assessments. And those genetically predisposed to characteristics associated with being a "night owl" also tended to eat meals at later times. And, statistically, there were no significant health issues tied to changes in lunch and dinner times, just breakfast.
"Later breakfast timing is also associated with increased mortality," the researchers noted. "Latent class analysis of meal timing trajectories identify early and late eating groups, with 10-year survival rates of 86.7% in the late eating group compared to 89.5% in the early eating group."
While this might sound like a chicken and eggs-on-toast scenario, these findings establish an association between late breakfast and increased risk of death, which could serve as an insightful health marker in older adults for early intervention and treatment.
“Our research suggests that changes in when older adults eat, especially the timing of breakfast, could serve as an easy-to-monitor marker of their overall health status," said Dashti. "Patients and clinicians can possibly use shifts in mealtime routines as an early warning sign to look into underlying physical and mental health issues.
“Also, encouraging older adults in having consistent meal schedules could become part of broader strategies to promoting healthy aging and longevity," he added.
As with any study of this kind, there are many limitations – the researchers didn't look at day-to-day variability, skipped meals or snacks throughout the day, nor were they focused on what was consumed across breakfast, lunch and dinner. While the study's models accounted for several confounders (smoking, for example), they did not factor in other markers such as physical activity. And a lot of the mealtime data relied on self-reporting, which comes with its own inaccuracies.
Nonetheless, it establishes links between health and mealtimes across a population that's poorly represented in chrononutrition studies to date. And factoring in mealtimes during health assessments could aid early intervention and lower risk of early death.
“Our findings help fill that gap by showing that later meal timing, especially delayed breakfast, is tied to both health challenges and increased mortality risk in older adults," Dashti added. "These results add new meaning to the saying that 'breakfast is the most important meal of the day,’ especially for older individuals.”
The study was published in the journal Communications Medicine.
Source: Mass General Brigham
