Habitual Fasting May Be Harmful for Older Adults

FRIDAY, Aug. 21, 2026 (HealthDay News) — Habitual fasting may be detrimental in older adults, according to a study published online Aug. 20 in the Journal of Internal Medicine.

Luis Kalmbach, from the Karolinska Institutet and Stockholm University, and colleagues examined the association between habitual fasting duration and chronic disease accumulation in older adults. The analysis included data from 2,981 participants (aged 60 years and older) in the Swedish National Study on Aging and Care.

The researchers found that compared with the lowest habitual fasting quartile (6 to 11.5 hours), participants in the highest quartile (14 to 24 hours) experienced steeper annual accumulation of total chronic diseases, cardiovascular diseases, and neuropsychiatric diseases. When stratifying by age, the association with total chronic disease accumulation existed in adults aged 78 years and older but not in those younger than 78 years. Findings persisted across sensitivity analyses addressing reverse causation, measurement bias, and residual confounding.

“Much of the research on fasting has been conducted in younger or middle-aged populations,” coauthor Adrián Carballo Casla, Ph.D., also from the Karolinska Institutet, said in a statement. “Our findings suggest that the associations may be different in older adults, particularly among the oldest age groups.”

Abstract/Full Text