Excerpt: 'You: On a Diet'

Nov. 15, 2006 — -- Most people cringe at the thought of going on a diet.

But doctors Mehmet Oz and Michael Roizen say dieting doesn't have to be so hard.

In their new book, "You: On a Diet: The Owner's Manual for Waist Management," the trusted doctors and best-selling authors reveal the secrets to shaving inches off waistlines everywhere.

The book motivates readers with the most effective fat-burning tool: knowledge. By understanding how the body's fat-storing and fat-burning systems work, readers will learn how to crack the code on true and lifelong waist management.

Chapter 1

The Ideal Body
What Your Body Is Supposed to Look Like

Diet Myths

The most common question heard among overweight people isn't "Can I have more sour cream?" It's "Why can't I lose weight?" While you may think you know the answer (severe pancake addiction), the real reason is biological:

We're actually hardwired to store some fat.

Our bodies have more systems that allow us to gain weight than to lose it. Historically, as we'll see in a moment, that served us well. Today, though, we've poisoned the systems that help us lose weight and empowered the ones that allow us to gain it -- botching up our anatomy and turning our bodies into fat-storing machines. One of your goals will be to reprogram your body so that your internal systems can work the way they did when the greatest enemy we faced was a charging wildebeest, not a cheese-drowned pork roll.

Our ancestors survived by gaining and storing weight to survive periodic famines. That has left our bodies prone to storing fat and gaining weight, tendencies that willpower alone can rarely overcome. To see how our bodies have morphed from rock-hard to sponge-soft, let's look inside the bodies of early man and woman. They looked like stereotypical superheroes: strong, lean, muscular, able to jump snorting mammals in a single bound.

As we evolved, we created systems and behaviors to survive when droughts and poor eyesight made picking and hunting less than successful. We learned to thrive, and we learned to eat. In early times, our diets consisted of fruits, nuts, vegetables, tubers, and wild meat -- foods that were, for the most part, low in calories. That's not to say our ancestors didn't enjoy their foods. They consumed their sugars through fruit, and they even splurged when they came across the Paleolithic Cinnabon -- a honeycomb. The difference between their splurges and ours? They came across the sweet treats only rarely; it's not as if they popped in for a 900-calorie sugar bomb every time they went shopping for a new buffalo hide. Add that to the fact that their definition of "searching for food" included walking, stalking, and chasing, not sliding the milk carton out of the way to find the pudding pack. It was a lot of work to get food, so they naturally burned many of the calories they consumed through the physical activity of hunting and gathering.

Because salt and sugar were scarce, our ancestors mostly feasted on grains, vegetables, and meats -- for good reason. The meat provided the protein, vitamins, minerals, and fatty acids that helped them grow taller and develop larger brains, while the other foods gave them nutrients such as glucose, a simple sugar found in fruit and the complex carbohydrates of plants, that they needed to grow and develop, and for energy to move. And, of course, food was always fresh, as there was no canning or refrigeration to store up food for Super Bowl parties, or to sneak in an 11 p.m. bowl of sugar-coated oats.