In fitness and nutrition world popular as ad libitum dieting, it is the most sustainable way of dieting since it does not require any calorie counting.
On the other side, calorie counting has become very popular in the past few years where you would use a mobile app like Myfitnesspal and log in everything you eat in a day.
I believe this is a great way to learn about food if you are new to fitness, as it teaches you how certain foods differ in calories and other nutrients, and how much food your body really needs.
I use this approach with all of my clients in the beginning as a stepping stone for their fitness journey. Once you understand basic principles of nutrition, you can proceed on to the next level which is ad libitum dieting.