How Many Times a Day Do You Feed Your Cat and What Brand?

My cats are so weird! If their bowl of Friskies dry food is a little bit low, they'll yowl until I top it off for them. I generally just keep a big bowl of food out for them every day, and let them eat whenever they want to. They don't seem to be overweight at all, so I don't worry about the amount they are eating. I give them treats of chopped turkey or roast beef, or the occasional can of tuna, split between the three of them, about every day. They don't seem to have any problem running off the calories.