Older adults who typically go 14 hours or more between their first and last meal of the day may build up chronic diseases faster than peers who eat within a shorter window. That is the takeaway from a new study from Karolinska Institutet, published in the Journal of Internal Medicine.
The researchers followed 2,981 Stockholm residents aged 60 and older for up to 15 years. People whose longest daily gap between meals ran between 14 and 24 hours accumulated chronic conditions more rapidly than those whose longest gap was 6 to 11.5 hours.
The pattern held for cardiovascular and neuropsychiatric diseases but not for musculoskeletal conditions. The link was most pronounced in participants aged 78 and older, a group largely left out of the research that has driven the popularity of intermittent fasting.
"Our findings suggest that the associations may be different in older adults, particularly among the oldest age groups," said Adrián Carballo Casla, a postdoctoral researcher at the Aging Research Center at Karolinska Institutet and the study's last author.
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What the study can and cannot show
This is an observational analysis, so it cannot prove that longer meal intervals cause faster disease accumulation. The researchers themselves stress that the data cannot establish whether the fasting pattern independently contributed to the outcome.
Older adults with long gaps between meals may also be sicker, frailer or more socially isolated to begin with. Those factors could drive both the eating pattern and the health decline.
Still, the finding matters because much of the fasting evidence comes from younger and middle-aged people. An earlier analysis from the same team in Nature Aging tied higher-quality diets to slower disease accumulation, while inflammatory eating patterns sped it up.
Why older bodies may respond differently
Aging changes how the body handles long stretches without food. Appetite falls, thirst signals weaken and nutrient absorption becomes less efficient. That makes it easier to fall short on protein, calcium, vitamin D and fiber during a compressed eating window.
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A review from the University of Florida warns that "age-related muscle loss, known as sarcopenia, is already a significant concern for older adults" and that fasting without adequate protein can worsen it.
The same review flags medication timing as a concrete risk. Many drugs common in later life either require food or directly affect blood sugar.
A May 2026 analysis of the evidence reported that very restrictive eating windows have been linked to 58 percent higher cardiovascular mortality in older adults. It concluded that for this age group, "moderation is not optional; it is necessary."
What this means for daily meals
The Karolinska team is not telling older adults to graze all day. The results suggest that the aggressive fasting protocols marketed to younger dieters may not translate cleanly to people in their late 70s and beyond.
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Anyone in this age group considering a change to when they eat, especially those on medication or living with diabetes, kidney disease or heart disease, should talk to their doctor first. As this and earlier studies show, the meal schedule itself is turning out to be a health variable in its own right, not just a side note to what is on the plate.
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This article is made and published by Jesper Bengtson, who may have used AI in the preparation.