Hair Loss With Rapid Weight Loss

The document discusses the relationship between rapid weight loss and hair loss, based on observations from over 200 subjects who experienced significant weight loss over periods ranging from 40 to 330 days. The study found that increased telogen hair counts were associated with loss of body cell mass, such as a significant negative nitrogen balance. However, when protein intake was increased during fasting to preserve nitrogen balance, hair loss was almost completely eliminated. The conclusion is that hair loss during rapid weight loss is due to the low priority of hair growth for available protein when dietary and mobilized body protein are insufficient to meet requirements, rather than the rapidity of weight loss itself. Hair loss is restored with refeeding and repletion of body cell mass, suggesting that there are no long-term consequences on hair growth from rapid weight loss, even if it is associated with negative nitrogen balance.