Is it bad to eat 900 calories a day, if i feel satisfied?

It's absolutely fine-everybody's body is different right? Different bodies need different calorie intakes, no matter their height and weight. when people tell you you need a certain number of calories for your height and weight, you should be AROUND that intake, but if you feel fine with less or more, it's fine simply because ur body doesnt need the same foods and such as any other person. You don't have the exact same body as anyone else.