As @crisw has said already, cats don’t have teeth that are designed for chewing. Instead, they have a mouth full of razor-sharp blades for slicing chunks off an animal and then swallowing the chunks whole.
Cats actually are designed to throw up rather easily. Scientists speculate that this could be an adaptation that allows them to get rid of toxins or bad food. In some cats, however, this mechanism is set a bit too delicately, so the cat throws up often (usually on something you care about or in a very difficult place to clean). If a cat has a food allergy or sensitivity, too, the body could interpret the food as a toxin. Thus, many cat owners are starting to avoid foods with corn in it or other grains as well.
Cats may regurgitate (ie “yak) because they are eating too fast. If you suspect this is the case there are new bowls specifically for puppies (but which could do the trick for cats) that make it impossible to bolt the food. You could also either feed multiple small meals instead of one or two large ones, or allow self-feeding, which works well if you feed only dry food.
There is also a type of nerve damage where the food sits in the cat’s esophagus instead of going on into the stomach, at least until the cat throws it up. Cats with this problem may be very thin or may show rapid weight loss because they are starving. If your cat, despite his new-found hobby, is still plump, active and healthy, with a shiny coat, then there he most likely has no disease as the cause.
In addition, there can be esophageal blockages or strictures, problems with the muscles of the esophagus, and other physical difficulties, which you can read about here . Even an undiagnosed case of pneumonia can cause a cat to regurgitate its food.
Another thing to watch for is the cat’s demeanor. If it suddenly throws up but right afterward returns to its normal, lovable self, then the cat probably is not feeling any nausea. Thus it really is just regurgitating the contents of its esophagus rather than vomiting the contents of its stomach.
A nauseous cat is a sick cat. They often drool, their haws can be raised, and they frequently go into what I call the “bad kidney crouch.” In this case, the cat needs to get to the vet ASAP because the conditions that cause nausea in cats can be rapidly fatal.
If your cat is throwing up daily, or if your cat is losing weight or looking ill, then take your cat in to the vet. Otherwise try non-grain containing food, multiple small meals or free feeding instead of one or two large ones, or try wet food instead of dry.