Is it better to leave the bowl always with food, or to put it when it's "time to eat"?
My cat has her bowl available 24/7 and I'm starting to worry that she might become obese. She seems to eat very often, though not in large amounts.
To start with, consider the answers to How many times a day should I feed a cat?
I've found it depends on the cat: most cats I've had would stop eating when they'd had enough. It's common for a cat to eat a little often: as long as the cat is not obese this is not a problem.
The method I've had vets recommend and that I've used with all my cats is to have dry food available at all times and a set mealtime with wet food. I've only had one cat where this method didn't work and it was necessary to feed her at specific times.
I'd only recommend not having dry food always available if the cat doesn't control her own food intake and is rapidly gaining weight or is already obese and needs to lose weight.
It is good that you can give your cat food at a fixed timing daily. Example Morning (one bowl of pallets), afternoon (one can food), night/evening (one bowl of pallets). If you continue to give your cat free-flow of food, it will become a habit for her; and after she get used to it, its very hard to control (just like what happened to my cat).
My cat gets to have one can of wet food each day at 5pm, and free-flow of dry food throughout the day. This is because for my case its very hard to control as my family members will "give-in" to her whenever she make a lot of noise (meowing non-stop) when she found that her bowl is empty. It had became a habit for her and she will make a lot of noise if there's no food in her bowl.
Recently, I had just started to control her food intake after 11pm at night as she's getting old. I feed her some dry food to make sure she will not be hungry throughout the night, and washed up the bowl.
FYI, my cat is obese after years of free-flow of dry food and it had became her habit which its very hard for us to control (as she will spray her urine anywhere if we do not give in to her and when she gets unhappy).
So in conclusion, DO NOT make it a habit for her and try to control the amount of food she eats if you do not want her to get obese.