The completion gap framework: age-associated weight gain as passive convergence between meal completion and energy demand

Age-associated weight gain is commonly attributed to behavioral or metabolic changes. We propose the completion gap framework, in which meal-completion requirements and physiological energy demand are only partially coupled. Persistent mismatch between these variables produces gradual weight gain until a higher equilibrium body weight is reached.

This systems-level perspective integrates existing regulatory models while generating experimentally testable predictions for aging, obesity, and nutrition. This work received no specific funding from any public, commercial, or not-for-profit funding agency. National Institutes of Health, Bethesda, MD, USA HealthTrace AI, Inc., Rockville, MD, USA L.C. is the founder of HealthTrace AI, Inc., which develops digital health technologies related to nutrition and metabolic monitoring.

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The completion gap framework: age-associated weight gain as passive convergence between meal completion and energy demand. npj Aging (2026). https://doi.org/10.1038/s41514-026-00503-5 DOI: https://doi.org/10.1038/s41514-026-00503-5