Aim to be healthy, not skinny. As you get older, your body will change and you will put on weight easier.
I have just lost 80lbs, and the BMI index says I need to lose another 40. My body definitely will not lose 40 more pounds, and I don’t want to be that skinny. I want to lose three more pounds and then I’ll have let my goal. I sit between a size 8-12 depending how things are made. I used to be a size 22.