A few years ago I decided that I needed to lose a little bit of weight. Foolishly, I just started eating less and less. My stomach shrank so all I was eating was two bowls of cereal a day. After about a year, my hair started to thin. My temples were bare and my hairline had thinned a lot. I would say I lost about 50% of my hair. Other warning signs of calorie restriction: my skin was so dry it was flaking off in big sheets, my heels were cracked and my fingernails were very slow growing. Also, I was feeling slow and exhausted. I was so desperate to stop my hair loss and I frantically researched everything. I finally found an article that was based on a study about severe calorie depletion. It said that severe calorie deficiency causes the thyroid to slow way down. My symptoms matched the symptoms for hypothyroidism. I met with a nutritionist who put me on a protein, vegetable and fruit diet. It felt weird to eat so much but I was determined to get my hair back. A year and a half has passed and I can report success. My temples and hairline have been filling in. The overall density has improved too. I'd say I have about 75% of my original hair density and I'm hoping for more improvement over the next 12 months.