The Paleo Diet (3 page)

But here’s the good news. Over the last twenty-five years, scientists and physicians worldwide have begun to agree on the fundamental principle underlying optimal nutrition—thanks in part to my colleague Dr. S. Boyd Eaton of Emory University in Atlanta. In 1985, Dr. Eaton published a revolutionary scientific paper called “Paleolithic Nutrition” in the prestigious
New England Journal of Medicine
suggesting that the ideal diet was to be found in the nutritional practices of our Stone Age ancestors. Although a few physicians, scientists, and anthropologists had been aware of this concept, it was Dr. Eaton’s writings that brought this idea to center stage.

Dr. Eaton applied the most fundamental and pervasive idea of all biology and medicine—the theory of evolution by natural selection—to diet and health. His premise was simple: our genes determine our nutritional needs. And our genes were shaped by the selective pressures of our Paleolithic environment, including the foods our ancient ancestors ate.

Many modern foods are at odds with our genetic makeup—which, as we’ll discuss in the book, is basically the same as that of our Paleolithic ancestors—and this is the cause of many of our modern diseases. By restoring the food types that we are genetically programmed to eat, we can not only lose weight, but also restore our health and well-being.

I have studied diet and health for the past three decades and have devoted the last twenty years to studying the Paleo Diet concept. I have been fortunate enough to work with Dr. Eaton to refine this groundbreaking idea and explore a wealth of new evidence. Together with many of the world’s top nutritional scientists and anthropologists, I have been able to determine the dietary practices of our hunter-gatherer ancestors. Understanding what they ate is essential for understanding what we should eat today to improve our health and promote weight loss. Our research has been published in the top nutritional journals in the world.

It’s all here for you in this book—all the dietary knowledge and wisdom that my research team and I have gleaned from our distant ancestors who lived in the days before agriculture. Part One explains what our Paleolithic ancestors ate, the basics of the Paleo Diet, and how civilization has made us stray from our original diet, bringing us ill health and obesity. Part Two shows how you can lose weight and how much you can lose, and also how the Paleo Diet can prevent and heal disease. Part Three spells out everything you need to know to follow the Paleo Diet—including meal plans for the three levels of the diet and more than 100 delicious Paleo recipes. That’s the best part of the Paleo Diet—you’ll eat well, feel great, and lose weight! The book ends with a complete list of scientific references that back up all of this information.

The Agricultural Revolution began 10,000 years ago—just a drop in the bucket compared to the 2.5 million years that human beings have lived on Earth. Until that time—just 333 generations ago—everyone on the planet ate lean meats, fresh fruits, and vegetables. For most of us, it’s been fewer than 200 generations since our ancestors abandoned the old lifestyle and turned to agriculture. If you happen to be an Eskimo or a Native American, it’s been barely four to six generations. Except for perhaps a half-dozen tiny tribes in South America and a few on the Andaman Islands in the Bay of Bengal, pure hunter-gatherers have vanished from the face of the Earth. When these few remaining tribes become Westernized during the next decade or so, this ancient way of life—which allowed our species to thrive, grow, and mature—will come to an end.

This loss of humanity’s original way of life matters a great deal. Why? Look at us. We’re a mess. We eat too much, we eat the wrong foods, and we’re fat. Incredibly, more Americans are overweight than aren’t: 68 percent of all American men over age twenty-five, and 64 percent of women over age twenty-five are either overweight or obese. And it’s killing us. The leading cause of death in the United States—responsible for 35 percent of all deaths or 1 of every 2.8 deaths—is heart and blood vessel disease. Seventy-three million Americans have high blood pressure; 34 million have high cholesterol levels, and 17 million have type 2 diabetes. It’s not a pretty picture.

Most people don’t realize just how healthy our Paleolithic ancestors were. They were lean, fit, and generally free from heart disease and the other ailments that plague Western countries. Yet many people assume that Stone Age people had it rough, that their lives were “poor, nasty, brutish, and short,” as Thomas Hobbes wrote in
The Leviathan
.

But the historical and anthropological record simply does not support this line of reasoning. Almost without exception, descriptions of hunter-gatherers by early European explorers and adventurers showed these people to be healthy, fit, strong, and vivacious. These same characteristics can be yours when you follow the dietary and exercise principles I have laid out in the Paleo Diet.

I have examined thousands of early-nineteenth and twentieth-century photographs of hunter-gatherers. They invariably show indigenous people to be lean, muscular, and fit. The few medical studies of hunter-gatherers who managed to survive into the twentieth century also confirm earlier written accounts by explorers and frontiersmen. No matter where they lived—in the polar regions of Canada, the deserts of Australia, or the rain forests of Brazil—the medical records were identical. These people were free from signs and symptoms of the chronic diseases that currently plague us. And they were lean and physically fit. The medical evidence shows that their body fat, aerobic fitness, blood cholesterol, blood pressure, and insulin metabolism were always superior to those of the average modern couch potato. In most cases, these values were equivalent to those of modern-day, healthy, trained athletes.

High blood pressure (hypertension) is the most prevalent risk factor for heart disease in the United States. It’s almost unheard of in indigenous populations. The Yanomamo Indians of northern Brazil and southern Venezuela, to whom salt was unknown in the late 1960s and early 1970s, were absolutely free from hypertension. Their blood pressure didn’t increase with age and remained remarkably low by today’s standards. Amazingly, scientific studies of Greenland Eskimos by Drs. Hans Bang and Jørn Dyerberg from Aalborg Hospital in Aalborg, Denmark, showed that despite a diet containing more than 60 percent animal food, not one death from heart disease—or even a single heart attack—occurred in 2,600 Eskimos from 1968 to 1978. This death rate from heart disease is one of the lowest ever reported in the medical literature. For a similar group of 2,600 people in the United States during a ten-year period, the expected number of deaths from heart disease would be about twenty-five.

When you put into practice the nutritional guidelines of the Paleo Diet, you will be getting the same protection from heart disease that the Eskimos had. You will also become lean and fit, like your ancient ancestors. This is your birthright. By going backward in time with your diet, you will actually be moving forward. You’ll be combining the ancient dietary wisdom with all of the health advantages that modern medicine has to offer. You will reap the best of both worlds.

What’s the diet craze this week? You name it, there’s a book selling it—and people buying it, hoping for a “magic bullet” to help them shed excess pounds. But how can everybody be right? More to the point, is
anybody
right? What are we supposed to eat? How can we lose weight, keep it off—and not feel hungry all the time? What’s the best diet for our health and well-being?

For more than thirty years, as an avid researcher of health, nutrition, and fitness, I have been working to answer these questions. I started this quest because I wanted to get past all the hype, confusion, and political posturing swirling around dietary opinion. I was looking for facts: the simple, unadulterated truth. The answer, I found, was hidden back in time—way back, with ancient humans who survived by hunting wild animals and fish and gathering wild fruits and vegetables. These people were known as “hunter-gatherers,” and my research team and I published our analysis of what many of them (more than 200 separate societies) ate in
The American Journal of Clinical Nutrition.
We were astonished at the diversity of their diet. We were also amazed at what they did
not
eat—which we’ll get to in a minute and which may surprise you.

What do Paleolithic people have to do with us? Actually, quite a lot: DNA evidence shows that basic human physiology has changed little in 40,000 years. Literally, we are Stone Agers living in the Space Age; our dietary needs are the same as theirs. Our genes are well adapted to a world in which all the food eaten daily had to be hunted, fished, or gathered from the natural environment—a world that no longer exists. Nature determined what our bodies needed thousands of years before civilization developed, before people started farming and raising domesticated livestock.

In other words, built into our genes is a blueprint for optimal nutrition—a plan that spells out the foods that make us healthy, lean, and fit. Whether you believe the architect of that blueprint is God, or God acting through evolution by natural selection, or by evolution alone, the end result is still the same: We need to give our bodies the foods we were originally designed to eat.

Your car is designed to run on gasoline. When you put diesel fuel into its tank, the results are disastrous for the engine. The same principle is true for us: We are designed to run best on the wild plant and animal foods that all human beings gathered and hunted just 333 generations ago. The staples of today’s diet—cereals, dairy products, refined sugars, fatty meats, and salted, processed foods—are like diesel fuel to our bodies’ metabolic machinery. These foods clog our engines, make us fat, and cause disease and ill health.

Sadly, with all of our progress, we have strayed from the path designed for us by nature. For instance:

With this book, we are returning to the diet we were genetically programmed to follow. The Paleo Diet is more than a blast from the past. It’s the key to
speedy weight loss, effective weight control, and, above all, lifelong health.
The Paleo Diet enlists the body’s own mechanisms, evolved over millions of years, to put the brakes on weight gain and the development of the chronic diseases of civilization. It is the closest approximation we can make, given the current scientific knowledge, to humanity’s original, universal diet—the easy-to-follow, cravings-checking, satisfying program that nature itself has devised.

The Paleo Diet is a low-carbohydrate diet—but that’s where any resemblance to the glut of low-carbohydrate fad diets ends. Remember, the Paleo Diet is the only diet based on millions of years of nutritional facts—the one ideally suited to our biological needs and makeup and the one that most closely resembles hunter-gatherer diets. How does the Paleo Diet compare with the low-carb fad diets and the average U.S. diet?

Modern low-carbohydrate weight-loss diets are really high-fat diets that contain moderate levels of protein. They don’t have the high levels of protein that our ancestors ate—the levels found in the Paleo Diet. Actually, compared with what our ancestors ate, the carbohydrate content of these modern weight-loss diets is far too low. Even worse, almost all of these low-carbohydrate diets permit unlimited consumption of fatty, salty processed meats (such as bacon, sausage, hot dogs, and lunch meats) and dairy products (cheeses, cream, and butter) while restricting the consumption of fruits and vegetables. Cancer-fighting fruits and vegetables! This dietary pattern is drastically different from that of our ancestors.

And although low-carbohydrate diets may be successful in promoting weight loss, many dieters are achieving short-term weight loss at the expense of long-term health and well-being. Here’s what the sellers of these diet plans don’t want you to know: when low-carbohydrate diets cause weight loss in the short term, it’s because they deplete the body’s reserves of muscle and liver glycogen (carbohydrate), and the weight you’re losing rapidly is mostly water weight.