Don't think much of your vet if his only comment was "a lot of cats do it..."

Actually you may have to try different types of food. Some cats are happy eating dried cat food, but many won't drink enough water for their stomaches to tolerate this. So you may have to introduce wet cat food and you may have to try various brands to hit on one they can tolerate.

As Sorcha says, you may also have to limit the amount of food you put out at any time.

If your cat goes out regularly, you may have to put up with a certain amount of puking if your cat has a tendency towards experimental outdoor quisine (i.e. will insist on trying everyting at least once to see if it's edible) never mind eating grass etc. for getting rid of furballs and also dealing with quisine experiments that have gone horribly wrong....

Normally once you figure out what sets them off, it's usually fairly easy to keep ahead of a cat's puking regime.