At 23, with 2 years of bodybuilding type diets under my belt.. (all meats, cheeses, milk, and eggs, and gotta have those carbz) I noticed my hair started thinning faster. I'd get tingling sensations around my scalp where I'm slightly balding. I think this is from a couple of things... Inflammation from grains and sugar in general, and chronically high insulin and correspondingly chronically high testosterone.
Since I've gone ZC for three months now, the tingling sensations have completely stopped, and I feel I won't lose my hair now keeping with this diet for the long-term. I plan on eating this way till I die.
My testosterone has lowered to a healthy level, I believe. That might be a bit misleading, as I don't really feel like my muscle comes in less, or my recovery takes longer. I think the unbalanced ratio of testorone:dht has been reversed, actually.