The Quetelet Dilemma - Technological Deficiency, Epistemological Apathy, and the Validation of BMI-C (Body Morphometric Index - Corrected) with NHANES 2015-23 Data

AbstratWhy is BMI (Body Mass Index) an inefficient tool for Primary Heath Care?BMI- proposed bu Quetelet in the 19th century, persists as as epidemiologicaland clinical tool, despite its well-known limitation: it does not distinguish fat massfrom lean mass, ignores tissue heterogeneity, and treats the body as planar (cm²)when it is volumetric (cm³). Criticisms of the method date back to quetelethimself, who already observed the variation in the weight-height relationshipthroughout development. Ancel Keys, when naming it the Body Mass Index(BMI), acknowledged its limitations for individual assessment but justified his choicedue to the technological unavailability of mor precise methods on a large scale - thesame limitation that existed in 1832. Nick Trefthen proposed a mathematicalrefinement as a solution - an exponent of 2.5 - which dos not resolve the problem ofheterogeneous body composition.We present BMI-C (Body Morphometric Index - Corrected), a proprietaryindex that incorporates the third dimension of the body. BMI-C achieves a correlationof 0,925 with trunk fat measured by DEXA - a value that approaches the goldstandard and has predictive capacity tha BMI lacks.The importance of this improvement goes beyond statistical precision. Bodycomposition determines oxygen availability and the body’s water reserve: caused byadipose tissue that, by compressing the lungs, reduces ventilatory capacity and, byreplacing muscle mass, decreases water reserve. This dual restriction - ventilatoryand metabolic - impacts fundamental processes such as the Krebs cycle andoxidative phosphorylation, which depend on an adequate aqueous environment formaintaining the proton gradient, mitochondrial integrity, and efficient ATP production.The gradual correction of BMI, by refining the estimate of the proportionbetween lean mass and fat mass, allows for more accurate assessment of theorganism’s metabolic efficiency - a dimension that BMI, due to its two-dimensionalnature, is incapable of capturing.