Weighing just four stone, extreme anorexic Valeria Levitin is thought to be the thinnest woman in the world. Her malnourished figure and matchstick-thin thighs should serve as a stark warning about the dangers of eating disorders.Weighing just four stone, extreme anorexic Valeria Levitin is thought to be the thinnest woman in the world. Her malnourished figure and matchstick-thin thighs should serve as a stark warning about the dangers of eating disorders.