It's okay to lose weight just through diet without exercise, right?

I was planning to start exercising, but realistically, the timing is a bit tight.

So I became curious if it is possible to lose weight just through diet.

I mean, I'm sure I'll lose weight, but I became curious if it's okay to lose weight like that.

I am concerned because there is talk of muscle loss and the possibility of a drop in basal metabolic rate.

I am wondering if there is a range that can be maintained without exercise.