The Effects of Fasting Regimens on Hydration, Electrolyte Balance, and Metabolic Biomarkers

Fasting regimens have gained widespread attention for their physiological and metabolic effects, yet their impacts on hydration, electrolyte balance, and metabolic biomarkers remain multifaceted and incompletely understood. This review synthesizes current literature examining how various fasting patterns influence hydration status, key electrolytes, glucose metabolism, uric acid levels, lipid profiles, and inflammatory markers across diverse populations. Findings indicate that fasting can modulate serum sodium, potassium, and uric acid, with implications for water-electrolyte homeostasis and renal function. Glucose regulation shows dynamic alterations during fasting, including shifts in ketone and blood glucose levels, with potential ramifications for cognitive function and diabetes risk. Lipid metabolism and inflammatory biomarkers also respond variably depending on fasting duration and population characteristics. Notably, challenges in maintaining hydration, especially during prolonged fasting or in special populations such as children and elderly, are highlighted. Despite substantial progress, gaps remain concerning the mechanistic pathways and long-term effects of fasting on these biomarkers. Future research should target these gaps, aiming to optimize fasting protocols for health benefits while minimizing adverse outcomes related to hydration and electrolyte disturbances.