3 Why Humans Can Use FBM · 3.3 Fatty Acids as Primary Energy Substrate
3.3 Fatty Acids as Primary Energy Substrate
Human Fat-Based Metabolism
This page is structured as definition, control variables, causal chain, observable outputs, and boundary, and serves as a canonical definition node in Human FBM.
This page defines the conditions under which fatty acids become the dominant long-term direct energy substrate.
Dominance requires both lower occupancy and sufficient energy at the same time.
Insulin occupancy determines fatty-acid mobilization threshold and persistence.
Body-fat availability and dietary fat jointly provide substrate sources.
Total energy and lean-mass stability determine whether the dominance pattern can persist.
When occupancy decreases, fatty-acid access expands and direct-energy share increases.
With sufficient energy and tissue stability, this share can remain dominant over time.
Meal-to-meal energy continuity strengthens and satiety rhythm becomes more predictable.
Body-fat allocation and intake stability become easier to maintain.
Higher fat intake alone does not prove dominant fatty-acid direct energy.
Substrate source variables cannot replace occupancy and sufficiency variables.