Alcohol is a tricky one, because its calories are an especially bad way of measuring impact on energy and weight.

It is kind of like measuring the calories of wood. It burns well, so it has a high calories, but metabolizes poorly. A block of wood is about 400 kCal/100g.

Ethanol has 1325 kJ/mol of energy. If the reaction stops part way through the metabolic pathways, which happens because acetic acid is excreted in the urine after drinking, then not nearly as much energy can be derived from alcohol, only 215.1 kJ/mol.

https://en.wikipedia.org/wiki/Pharmacology_of_ethanol#Metabo...