it's basic thermodynamics if it's 1:1
the body doesn't burn food, it metabolizes food.
i'm not a bio chemist, but i question the notion that the breaking of molecular bonds during combustion releases the same amount energy as body metabolism and subsequent ATP production does and that process varies based on the macro being metabolized on the cellular level from what i've heard and read. alcohol is particularly interesting because it is not a macro nutrient and the metabolic processes and pathways that would lead to it accumualating fat on the body are markedly different than how macro nutrients would.
there's even suggestions in the research that complicated processes in the microbiome will decrease the amount of calories you assume to have ingested before they can even move into the body for ATP production and storage.