The Hydration of Adipose Tissue — The Circuit Linking Water and Fat, and the Instrument That Cannot Measure It

Thu, 06 Aug 2026 09:00:00 +0900

1. Abstract

Body composition analyzers routinely report that total body water changes little during weight loss. This finding is more likely an artifact of the measurement model than a physiological fact, because standard bioelectrical impedance analysis (BIA) is built on the assumption that adipose tissue contains neither intracellular nor extracellular fluid. Recent physiology has described a circuit that contradicts that assumption. The adipocyte membrane carries a channel that conducts both water and glycerol (aquaporin-7, AQP7), and the more obstructed this water pathway becomes, the more lipid accumulates. As adipocytes enlarge, hypoxia and inflammation follow, interstitial fluid increases, and within that interstitium sodium is stored without accompanying water. Tonicity-responsive enhancer binding protein (TonEBP), which senses this local hypertonicity, epigenetically represses the β3-adrenergic receptor, the central switch for lipid oxidation. Water and fat therefore do not stand in a one-directional causal relationship but form a mutually reinforcing loop. This paper organizes that circuit into four layers and identifies the points at which clinical instruments fail to observe it.

아쿠아포린 on Sowonjae — Studies in Sasang Constitutional Medicine

The Hydration of Adipose Tissue — The Circuit Linking Water and Fat, and the Instrument That Cannot Measure It

1. Abstract