Why Dieters’ Hairlines Sometimes Recede Along With Their Waistlines:
In a healthy person, hair typically grows about an inch every two months. Hair has a three-phase life cycle — the growing phase can last two to five years. A second, less-active phase lasts only about six weeks. A final resting phase lasts three to five months, before the hair falls out and new hair grows in. About 15% of hair follicles are in the resting phase at a time.Abrupt changes in nutrition can disrupt the hair-growth cycle, causing hair follicles in the growing phase to convert to the resting phase too soon. This can mean a 20% to 30% or more increase in the number of daily hairs shed.