Again, it is not about weight, it is about fitness level. If you are 180 lbs. @ 45% body fat you're going to have a hard time getting yourself down the aisle, let alone anyone else. 180 lbs. @30% body fat is a totally different story. That is for a woman. Take off 8-10% for a man. Women need and thus hold more fat naturally than men do.

For a woman, 20% or lower body fat is getting pretty lean. For men 12% or less is getting pretty lean.

People who talk about Hollywood stars with 4% body fat have no idea what they are talking about.