| _version_ | 1866901740708691968 |
|---|---|
| author | Mokhdum Azam Mashrafi, Mokhdum Azam Mashrafi |
| author_facet | Mokhdum Azam Mashrafi, Mokhdum Azam Mashrafi |
| contents | <p><span>Human metabolism is traditionally interpreted through caloric balance, muscular efficiency, and biomechanical work output. However, extensive physiological and calorimetric evidence demonstrates that only a small and remarkably invariant fraction of dietary chemical energy is converted into sustained external mechanical work, even under conditions of high caloric intake, optimized nutrition, and intensive physical training. This persistent discrepancy has often been attributed to behavioral factors, evolutionary trade-offs, or biological inefficiency. In this work, we show that such interpretations are incomplete and that the dominance of survival-related energy expenditure in human metabolism arises from fundamental thermodynamic constraints rather than suboptimal biological design.</span></p> <p><span>We analyze human metabolism using a unified energy survival formulation,</span></p> <p><span>Ψ=AE/TE+ε,</span></p> <p><span>where AE represents absorbed chemical energy from food, TE denotes transport and distribution losses associated with circulation, diffusion, and biochemical coupling, and ε captures irreducible entropy-generating losses mandated by the second law of thermodynamics. This formulation explicitly distinguishes energy absorption from energy survivability, quantifying the fraction of metabolic energy that remains available for conversion after unavoidable dissipation through regulation, maintenance, and entropy production.</span></p> <p><span>By coupling the survival factor Ψ with an internal conversion capacity term Cint, representing physiological throughput limits imposed by oxygen delivery, mitochondrial kinetics, neuromuscular signaling, and heat rejection, we apply the universal performance law</span></p> <p><span>Euseful=Ein</span><span>⋅</span><span>Ψ</span><span>⋅</span><span>Cint</span></p> <p><span>to human physiology. Quantitative synthesis of metabolic data shows that basal cellular maintenance, thermoregulation, neural activity, organ function, immune surveillance, and molecular repair necessarily consume approximately 80–95% of absorbed dietary energy under normal conditions. The remaining fraction available for sustained external mechanical work is therefore intrinsically bounded, typically to below 5–10% of total energy intake, independent of caloric availability.</span></p> <p><span>These limits emerge naturally from survival-dominated energy pathways and internal conversion saturation, without invoking behavioral constraints or inefficiency assumptions. The results demonstrate that human metabolism operates in a survival-limited regime in which external work is a secondary by-product rather than a primary energetic objective. This places human metabolic systems in the same physical class as other survival-dominated systems—such as ecosystems, photosynthetic organisms, and large-scale information-processing infrastructures—thereby validating the universality of the proposed ΨΨ-based energy law across biological and engineered domains.</span></p> <p>Please check the attachment for details</p> |
| format | Recurso digital |
| id | zenodo_https___doi_org_10_5281_zenodo_18673288 |
| institution | Zenodo |
| language | |
| publishDate | 2026 |
| publisher | Zenodo |
| record_format | zenodo |
| spellingShingle | A Unified Thermodynamic Law of Useful Energy: Survival and Conversion Constraints in Human Metabolism Mokhdum Azam Mashrafi, Mokhdum Azam Mashrafi <p><span>Human metabolism is traditionally interpreted through caloric balance, muscular efficiency, and biomechanical work output. However, extensive physiological and calorimetric evidence demonstrates that only a small and remarkably invariant fraction of dietary chemical energy is converted into sustained external mechanical work, even under conditions of high caloric intake, optimized nutrition, and intensive physical training. This persistent discrepancy has often been attributed to behavioral factors, evolutionary trade-offs, or biological inefficiency. In this work, we show that such interpretations are incomplete and that the dominance of survival-related energy expenditure in human metabolism arises from fundamental thermodynamic constraints rather than suboptimal biological design.</span></p> <p><span>We analyze human metabolism using a unified energy survival formulation,</span></p> <p><span>Ψ=AE/TE+ε,</span></p> <p><span>where AE represents absorbed chemical energy from food, TE denotes transport and distribution losses associated with circulation, diffusion, and biochemical coupling, and ε captures irreducible entropy-generating losses mandated by the second law of thermodynamics. This formulation explicitly distinguishes energy absorption from energy survivability, quantifying the fraction of metabolic energy that remains available for conversion after unavoidable dissipation through regulation, maintenance, and entropy production.</span></p> <p><span>By coupling the survival factor Ψ with an internal conversion capacity term Cint, representing physiological throughput limits imposed by oxygen delivery, mitochondrial kinetics, neuromuscular signaling, and heat rejection, we apply the universal performance law</span></p> <p><span>Euseful=Ein</span><span>⋅</span><span>Ψ</span><span>⋅</span><span>Cint</span></p> <p><span>to human physiology. Quantitative synthesis of metabolic data shows that basal cellular maintenance, thermoregulation, neural activity, organ function, immune surveillance, and molecular repair necessarily consume approximately 80–95% of absorbed dietary energy under normal conditions. The remaining fraction available for sustained external mechanical work is therefore intrinsically bounded, typically to below 5–10% of total energy intake, independent of caloric availability.</span></p> <p><span>These limits emerge naturally from survival-dominated energy pathways and internal conversion saturation, without invoking behavioral constraints or inefficiency assumptions. The results demonstrate that human metabolism operates in a survival-limited regime in which external work is a secondary by-product rather than a primary energetic objective. This places human metabolic systems in the same physical class as other survival-dominated systems—such as ecosystems, photosynthetic organisms, and large-scale information-processing infrastructures—thereby validating the universality of the proposed ΨΨ-based energy law across biological and engineered domains.</span></p> <p>Please check the attachment for details</p> |
| title | A Unified Thermodynamic Law of Useful Energy: Survival and Conversion Constraints in Human Metabolism |
| url | https://doi.org/10.5281/zenodo.18673288 |