It's crucial that you have some kind of schedule for feeding time with your Birman cat. I know it may seem easy to just leave a huge bowl of food out so that they can eat whenever they want but that's probably the worst thing you could do. Many cats will eat even when they are not hungry and this can lead to cat obesity and cat obesity can lead to many more serious health issues and could possibly even be fatal.
Another important factor in feeding your cat is the kind of food you are buying. You don't want to buy the cheapest you can find considering many of these low end foods have tons of fillers in them and they are lacking in the nutrition department. It also depends on how old they are and if they have allergies. These are all things to keep in mind. I feed my senior cats food that is specifically targeted to their age. You shouldn't be feeding your senior cat kitten food or vice versa.
Learn how to read the labels on the cat food before purchasing it. If you can't figure out what to look for then do some research, speak with your vet or you can even make your own food, this way you know exactly what they are getting.
