Long gaps between meals may accelerate chronic diseases in older adults, Swedish study suggests

Original publisher: Nature reports on a Swedish aging study analyzing meal timing in 2,981 adults aged 60 and over. Tracking the longest daily fasting gap, researchers found that those who regularly went 14 to 24 hours without eating developed chronic diseases faster than peers with shorter gaps, with the strongest signal in those aged 78 and older. The authors caution that the study is observational and that applying guidelines based on younger adults to late life may be inappropriate given nutritional vulnerability and polypharmacy. The findings invite a more nuanced view of fasting in older age.

• Older adults with long daily fasting were linked to faster accumulation of chronic diseases including heart disease and dementia.
• Age matters; no clear association among 60 to 77 year olds.
• Observational design limits causal conclusions; other factors could drive skipping meals.
• Implications for age specific dietary guidance and nutrition preservation in late life.

Overview and context

The article summarizes a Swedish observational study that followed 2,981 adults aged 60 and over, enrolled in a long-running aging cohort between 2001 and 2004. At baseline, the average participant was 74 years old. Over up to 15 years of follow-up, researchers collected diagnoses from medical examinations, histories, medications and registers to track the pace of development of chronic diseases. The study focused on the longest interval people typically went without consuming food or drink over a 24‑hour day, rather than participants following a predefined fasting regimen.

Study design and population

Participants were divided into four groups based on typical daily fasting duration, with the shortest group fasting six to 11.5 hours and the longest group fasting 14 to 24 hours. By comparing disease incidence and the rate at which the number of chronic conditions increased, researchers assessed whether longer gaps between meals correlated with faster disease accumulation, and whether age modulated any observed associations.

Key findings

The main result was that individuals with daily fasting intervals of 14–24 hours developed chronic diseases faster than those with shorter fasting periods. The diseases encompassed a broad range, notably cardiovascular conditions such as heart failure and stroke, as well as neuropsychiatric disorders including dementia and depression. In contrast, musculoskeletal diseases such as arthritis and osteoporosis did not show a difference across fasting groups. Importantly, age modified the association: among participants aged 78 and older, longer fasting was associated with faster disease accumulation; among those aged 60–77, no clear pattern emerged.

Possible interpretations and mechanisms

Researchers discuss several biologically plausible mechanisms that could explain age-related differences in fasting responses. Ageing can impair digestive efficiency and nutrient absorption, potentially amplifying nutrient deficits when meals are compressed into shorter windows. Regular, evenly distributed protein intake is linked to muscle maintenance, while long gaps could reduce anabolic signaling and contribute to muscle loss in older adults. Medication timing and interactions could also influence health outcomes, since some drugs require food for optimal absorption or can affect blood sugar if taken away from meals. The authors emphasize that these are plausible mechanisms but not proven by their observational data.

Strengths, limitations, and implications

The study leverages a well-characterized, long-running aging cohort with comprehensive health data and long follow-up. However, it remains observational and cannot establish causality. The meal timing data were collected more than two decades ago, which may limit generalizability to current populations with evolving dietary patterns. Confounding factors such as frailty, comorbidity, energy and protein intake, physical activity, and social factors were accounted for, but residual confounding cannot be ruled out. The findings suggest that aging populations may require nuanced, age-specific guidance on meal timing and nutrition, rather than a one-size-fits-all approach to fasting in late life. In sum, the research challenges the blanket application of younger-adult fasting patterns to older adults and highlights the need to consider nutritional vulnerability and existing health conditions when advising on meal timing.