What's the diameter of thin arms, legs and waist?

What is the range in diameter that is considered thin in these areas
Arms?
Legs?
Waistline?

Doesn't really matter what the diameter is, as long as your comfortable with yourself and not excessively overweight or underweight. Both extremes can cause severe health issues!

Also, your bone structure will cause a difference in how big of a diameter your arms, legs or waist is. For a long time, I had a 24 inch waist...I'm a bit out of shape now, but am working on getting back to that size.