Ballerina body, it’s a thing and that thing ain’t got one. From worldwide ballet.net:

What is the ideal weight for a prima ballerina?

This “look” is said to have the ability to create perfect, balletic lines and expressive movements on stage. The average height of an American ballerina is about 5 foot 2 inches to 5 foot 8 inches. In correspondence to height, weight would ideally range from 85 to 130 lbs.