With much sassy humor (they describe the adrenals as similar in shape to Mr. Potato Head's hat), they give a guided tour of the body's anatomy and major systems (hormonal, nervous, digestive, sensory, etc.) including plenty of fascinating trivia along the way. How often should you get your thyroid level checked? How much gas does the average person produce in a day? And, most importantly, how many times a year do most people have sex?? Drs. Oz and Roizen know. They also reveal plenty of bizarre (and potentially life-saving) facts such as this: If your earlobe has a prominent vertical wrinkle, it's likely that your arteries are aging faster than they ought to be. If only 8th-grade health class had been this fun.

The docs' main goal in presenting all this info is twofold: firstly, it's your body, so shouldn't you finally learn how it works? And, secondly, they want to help teach ways of preserving the body's health and youthfulness. To that end, they've included an "Owner's Manual Diet," a 10-day menu plan designed not for weight loss, but to make you feel "years younger." Its simple recipes are each meant to benefit a certain body system, such as Tomato Bruschetta, packed with the antioxidant lycopene, which has been proven to boost immunity. --Erica Jorgensen