But when your body is in keto, it does not have much glycogen present in the bloodstream. Alcohol is quickly sent to your liver and converted to acetaldehyde to be metabolized faster, so you probably feel more intoxicated more quickly. Even if you eat beforehand, "a protein-rich meal does not have as much significant effect [in slowing down the intoxication]," says Ax. The end result: you get drunk faster, which in turn leads to a terrible hangover.
https://www.youtube.com/watch?v=F8VaBzVm-EA