Background: Prolonged fasting as a dietary strategy has been linked to metabolic benefits; however, data supporting these benefits corresponded to studies in very small samples of young participants in controlled environments, with few cardiovascular risk markers, who were studied for short periods of time.
Objectives: We sought to assess the association of habitual prolonged nightly fasting with a wide array of cardiovascular, renal, inflammation, and nutritional status biomarkers among community-dwelling older adults.
Methods: Cross-sectional analysis of data were obtained from 1047 adults aged ≥65 y from the Seniors Study on Nutrition and Cardiovascular Risk in Spain 2 (Seniors-ENRICA-2) cohort. Habitual diet was assessed through a validated diet history. Fasting time was classified into the following categories: <10, 10 to <12, and 2 h/d, the latter being considered prolonged nightly fasting. Adjusted geometric means of biomarker concentrations in blood and serum were estimated using linear regression models, by categories of fasting time. Main confounders included overall diet quality, defined as adherence to a Mediterranean diet score, and BMI (in kg/m2).
Results: Longer fasting time was associated with: lower concentration of HDL cholesterol (difference between the longest and shortest fasting category: -2.94 mg/dL; 95% CI: -4.80, -1.09; P-trend: 0.01); higher potassium concentration (0.11 mEq/L; 95% CI: 0.03, 0.19; P-trend: 0.01); and lower concentration of chloride (-0.50 mEq/L; 95% CI: -0.91, -0.09; P-trend: 0.03). These results were slightly attenuated after additional adjustment for BMI.
Conclusions: Habitual prolonged nightly fasting did not show beneficial associations with the examined biomarkers. By contrast, some modest detrimental associations were found suggesting that extended periods of time between meals may not be beneficial for older adults.
Keywords: cardiovascular risk biomarkers; cross-sectional; health-related biomarkers; intermittent fasting; older adults; time-restricted feeding.
© The Author(s) 2022. Published by Oxford University Press on behalf of the American Society for Nutrition.