Definitely a fair question. There are probably a lot of factors that play into it. One of them being the distention of your stomach. If you are drinking several beers and simulating a full stomach then these signals may be enough to overcome the other signals from the brain that say you should eat something. The other piece may be the way you process alcohol. If you are very hungover prone you may process alcohol and its metabolites less efficiently. This could cause you to feel more hungover the next day, but it may also be telling your body "hey this intermediate metabolite feels like poison, lets not eat any more so we don't ingest more of it." It is the intermediate products of alcohol breakdown that are the reason you feel so crappy after drinking a whole bunch. Think of a time when you drank too much and got nauseous and threw up. This is your body trying to get rid of the alcohol because you overdid it and cant process it all. Some people process it less efficiently than other and therefore have a lower threshold for alcohol in general. Meaning you get that "I better not ingest anything more" signal from your body more easily. Also this whole comment is filled with speculation about you, but they are some reasons it may be occurring.