Buzzy vomits

My male cat buzzy is two years old and is an indoor only cat. Is it normal that he vomits after eating about every two weeks? When this happens, he vomits about 3 times until there is just foam. He sounds horrible and makes a lot of chucking noise while he is doing this. When he is through, he eats some catnip that I have growing for him. Then he starts begging for more food. Otherwise, he seems perfectly healthy. I have to feed him Hills overwieght high fiber twice a day (he's been overweight and had anal sacs problems). I can't leave any dry food out because he will overeat. I'm wondering if this is something to do with a hairball. I've never seen him vomit fur, but it seems like this condition happens more frequent in the summer. I've been brushing him daily, even though he is a short hair. Does anyone think I should call the vet?

This much vomitting isn't normal. I'd suggest the vet.

Could be hairball problems. Try giving him some hairball remedy and see if it helps. But you can always call the vet and get their opinion.