Well, I will give you a short lesson on the differences between vomiting and regurgitation, and will assume, your cat is most likely regurgitating. When an animal or person vomits, they feel nauseated, their mouth water and they tend to wretch and heave (I know, this is totally gross) and then they actively expell contents from the stomach. This usually happens a few minutes or hours after eating, depending on the circumstances. With regurgitation, they tend to just "burp" up the food, without the active heaving and nausea- the food seems to come back up almost effortlessly. The reason the destinction is important, is because the causes for each are so different.
From what you are describing, it sounds like your kitty is REALLY hungry, likely because no food is making it into his stomach. This could be due to an obstruction (blockage) anywhere in the esophagus on the way to the stomach. The most likely cause would be a hairball that gets stuck there, and less likely causes would be tumor or other foreign object blocking it. There is also the possiblity, that if you kitty really is eating so voraciously and quickly, that he is eating too much too fast and causing irritation in his esophagus and regurgitation.
If this is happening every day, please seek emergency attention as soon as possible! Please let us know what happened and we wish you and your kitty good health!