Janice Stanger, PhD, is author of The Perfect Formula Diet and a genius at getting other people to become nutritional geniuses. Her approach to any topic - diabetes, pregnancy, hormones, whatever - is to dig down into first principles and build from there.

This way of thinking helps non-experts understand the issues without having to rely on experts or gurus to tell them what to think. Grok the first principles, and you can build your own understanding on any topic.