<p> LANA ASPREY, M.D. , is a Karolinska-trained physician who runs an international natural fertility consulting practice, helping couples recover fertility using techniques outlined in The Better Baby Book . She is the former medical director of a lab testing company working with neurological immunity to environmental factors and practiced medicine in Stockholm, Sweden.</p> <p> DAVE ASPREY, MBA , is a well-known blogger on health and human performance. As "the Bulletproof Executive," he's been featured on ABC's Nightline and CNN and in Vogue and Men's Health . For nearly a decade, he's run the Silicon Valley Health Institute, an anti-aging nonprofit education group.</p>