The Paleo Solution: The Original Human Diet
I have to say: I'm impressed. If you would like insight into why a "Paleo" nutritional approach works on a biochemical level--why you lose weight, burn fat, and gain overall better health--then Robb's book 
Robb has a particular knack for organizing and presenting information in a way that makes it immediately accessible. You will gain an appreciation for how far American nutritional habits have veered off course.
Because Robb brings expertise from his academic biochemistry background, as well as personal trainer and educator running a successful gym in northern California, NorCal Strength and Conditioning, he delivers a book packed with information that is extremely easy to convert to immediate action in health and exercise. He seems to anticipate all the little problems and objections that people come up with along the way, dealing with them in his characteristic lighthearted way, providing practical, rational solutions.
Robb's book nicely complements what Dr. Loren Cordain has written in his The Paleo Diet: Lose Weight and Get Healthy by Eating the Food You Were Designed to Eat
If nutrition has you stumped, if the USDA food pyramid still sounds like a reasonable path, or if you just would like to understand nutrition a little bitter, especially its biochemical ins and outs, Robb's book is a wonderful place to start.