Better insulin sensitivity with insulin secretion → Less lipolysis → Less free-fatty-acids → Increased SHBG binding capacity → More testosterone → More libido.
SHBG increases testosterone. Low SHBG = Low testosterone. Low-fat/high-fiber vegan diet based around complex-carbohydrates is the best way to increase SHBG and testosterone.
http://www.longecity...sterone-levels/
According to wiki (emphasys mine): SHBG inhibits the function of sex hormones, testosterone included, since it binds them. It decreases with high levels of insulin, so more free T is bioavailable, libido is higher (other things beingequal). Is wiki wrong??
Testosterone and estradiol circulate in the bloodstream, bound mostly to SHBG and to a lesser extent serum albumin and corticosteroid-binding globulin (CBG) (AKA transcortin). Only a very small fraction of about 1-2% is unbound, or "free," and thus biologically active and able to enter a cell and activate its receptor. SHBG inhibits the function of these hormones. Thus, bioavailability of sex hormones is influenced by the level of SHBG. The relative binding affinity of various sex steroids for SHBG is dihydrotestosterone (DHT) > testosterone > androstenediol > estradiol > estrone.[4] DHEA is weakly bound to SHBG as well, but DHEA-S is not.[4] Androstenedione is not bound to SHBG either, and is instead bound solely to albumin.[5]....
SHBG has both enhancing and inhibiting hormonal influences. It decreases with high levels of insulin, growth hormone, insulin-like growth factor 1 (IGF-1), androgens, prolactin and transcortin. High estrogen, and thyroxine cause it to increase.