Fasting: How Many Consecutive Days?

Good morning, everyone. Today I’m starting the practice of fasting for the first time, with one large meal and two smaller ones. I’ve already read the thread here on the forum about this, but I still have a question and would like some help: for how many days is it recommended to fast in this way? Is there a limit that is generally advised, or is it left to the discretion of the faithful? I’m a bit concerned it could be harmful to health. Just to note: I have no pre-existing conditions, I’m male, and I’m 34 years old. Thank you to everyone who can help.