Extreme dieting can cause hair loss
Rapid weight loss or extreme diets can lead to hair loss, according to an article by the american hair loss council. Dieting as a cause of hair loss seems to be mostly associated with female pattern baldness. According to the article, any rapid change in body weight can lead to thinning of the hair, but it doesn’t always.
Certain medications, stress, physical stress on the body, and even too much Vitamin A can also contribute to hair loss. Here’s a snippet of the AHLC article:
Hair loss may also occur due to dieting. Franchised diet programs which are designed or administered under the direction of a physician with prescribed meals, dietary supplements and vitamin ingestion have become popular. Sometimes the client is told that vitamins are a necessary part of the program to prevent hair loss associated with dieting. From a dermatologists’s standpoint, however, the vitamins cannot prevent hair loss associated with rapid, significant weight loss. Furthermore, many of these supplements are high in vitamin A which can magnify the hair loss.
Source: http://www.ahlc.org/causes-f.htm