A lit weekend night out typically results in a large consumption of alcohol, and perhaps some major regrets the day after. You might've also noticed that a night of drinking leads to ravenous hunger the next morning as well. Like, the "I'm going to eat everything in the kitchen and still be hungry" type of hunger.
After eating everything in sight you might wonder why this is. Well, put down your breakfast sandwich (and/or whatever else you're eating) and listen up, because it's time to get educated.
The answer to your question of "Why am I so hungry?" (along with maybe, "Why does my head hurt so bad?") is that drinking alcohol causes a temporary decrease in your blood sugar levels. This is because your body reacts to it as if it's a toxin, and then channels all its energy in expelling it.
Bodily processes are then interrupted, including your liver, which is busy metabolizing all the alcohol you're drinking. Thus, it neglects to produce glucose like it usually does. If you drink on an empty stomach, the blood sugar drop is even more dramatic. The next day, your body's blood sugar levels are super out of whack, and so to readjust your body goes into desperate hunger mode.
Additionally, drinking inhibits the production of glutamine, a stimulant of the brain that deals with sleep, blood pressure, and metabolism. When you've stopped drinking, your body tries to catch up by making even more glutamine than it needs, leading to extreme hangriness.
Typically when we're feeling super hungry and hungover after a night out we crave fatty, greasy foods that we believe will save our pounding headaches. Scientists believe this is because our typical controlled inhibitions are weakened by alcohol.
Also, all the post-drinking eating you're probably doing may be having a negative effect on your health. Obviously, fatty and calorie-filled foods you crave aren't doing wonders for your bod, but higher alcohol consumption overall is associated with general weight gain. Sugary alcoholic drinks don't help too much either.