What does to make a pig of oneself mean?

Many people relate pigs, the animal, to some characteristics some human beings can have. Among those relations, the act of eating too much is the most common one. Some people can even call someone a pig if the person has the habit of eating a lot, making frequently too much noise while eating. There's an expression containing the word pig that can be used more generally if someone's eating too much, noisily, too fast, just like a pig does. Imagine for example you're at a birthday party and you notice your friend eating like desperate, as if he was without eating in ages. You then come up to him and say: Don't make a pig of yourself! You can also say that your friend was pigging out on chocolate cake and all the snacks he could put his hands on.