The Paleo Diet (16 page)

The Paleo Diet will also improve your mental outlook because it normalizes your insulin level. Almost everyone knows that a low blood sugar level can make you feel tired, irritable, and tense. When you normalize your insulin level with low-glycemic carbohydrates and plenty of lean protein, your blood sugar level will be more even throughout the day and so will your mood.

In the United States the common vitamin deficiency diseases (beriberi, pellagra, and rickets) were wiped out after World War II with the wide-scale fortification of our white flour and white rice with B vitamins and our milk and margarine with vitamin D. However, people living in less developed nations are not so lucky; these diseases still run rampant wherever diets are heavily based on cereals and legumes. It goes without saying that the world’s primary vitamin deficiency diseases, including scurvy from a lack of vitamin C, are completely a result of agriculture’s new foods. When you eat the way nature intended, you will protect yourself from all illnesses that develop from vitamin deficiencies.

Nearly all archaeological studies of Paleolithic people’s teeth show them to be almost completely free of cavities. How can this be when they never brushed, gargled with mouthwash, or flossed? The answer is simple: with their diet of lean meats, fruits, and veggies, cavities simply couldn’t get a foothold. Historically speaking, cavities and tooth decay didn’t start until the coming of agriculture and its starchy, sugary foods. Cavities are caused when acid produced by certain bacteria eats away part of the enamel of your tooth. These bacteria can’t set up shop in your teeth unless there is a constant source of sugar or starch that fuels their acid production.

We can learn a lot from our teeth because any food that does so much damage to our teeth can’t be very good for the rest of our bodies, either. Refined sugars and starches are foreign substances to our Paleolithic bodies. We simply haven’t had time to adapt to agriculture’s new foods. We are best designed to run on the foods nature provided: lean meats, fruits, and veggies.

Alcohol—and its enormous potential for abuse—was not part of the preagricultural equation. No alcoholic beverage has ever been linked to Paleolithic people, although it would have been possible to make alcoholic drinks from gathered honey (mead) or berries (wine) by natural fermentation. It wasn’t until the Agricultural Revolution, with its abundance of starchy grains, that the first beers were brewed on a regular basis. Quite a bit later came wine, made from fermented grapes. (Because beer and wine are yeast fermentation by-products, they do not contain more than about 6 to 13 percent alcohol; the alcohol-producing yeast organisms die when the alcohol concentration rises above this level.) Hard liquor didn’t come on the scene until about 800 A.D., with the invention of distillation.

In most Western countries, moderate consumption (five to ten drinks per week) of alcohol is not considered detrimental to health; in fact, it has been associated with a reduced risk of dying from all combined causes of death. Moderate alcohol consumption also may improve your insulin sensitivity and is associated with a reduced risk of other chronic diseases.

Does this mean you should take up drinking to improve your health? Absolutely not. You don’t need alcohol to obtain the health and weight-loss benefits of the Paleo Diet. However, if you currently enjoy an occasional glass of wine, there is no need to forgo this pleasure. Consumption of alcoholic beverages a few times a week won’t hurt your health, nor will it slow your weight loss. However, if you suffer from an autoimmune disease or another serious health problem, alcoholic beverages should not be part of your dietary equation.

Skin cancers come in three basic varieties:

The American Cancer Society estimated that 2 million Americans would develop the first two types of skin cancer in the year 2010. These cancers grow slowly, rarely spread to other areas of the body, and are easily curable by early removal. An estimated 69,000 Americans were expected to develop melanoma in 2009. If detected early and surgically removed before they spread to other parts of the body, melanomas are highly curable, with 95 out of 100 people alive five years after diagnosis. But if melanomas spread to the rest of the body, they can be deadly; the five-year survival rate drops drastically, to 16 out of 100.

Scientists know that excessive sunlight exposure is linked to all three cancers. But this does not mean you should avoid sunlight in any amount. Here again, the experience of our hunter-gatherer ancestors proves helpful. Ironically, many studies have shown that people with high lifetime sunlight exposure (similar to that of hunter-gatherers) have lower rates of melanoma than those with low sunlight exposure. Also, indoor workers have a greater risk of developing melanoma than outdoor workers do. Even more puzzling, melanomas often arise in body areas that are infrequently or intermittently exposed to the sun. These unexpected findings have led researchers to believe that severe sunburn during childhood, or intense burns in body areas that are infrequently or intermittently exposed to the sun, may be more important in the development of melanoma than cumulative exposure during adulthood.

When your exposure to sunlight is gradual, moderate, and continuous—if you don’t get excessive sunburn—your body responds in a manner guided by evolutionary wisdom. The skin begins to tan from increased production of melanin, and the darkened skin provides protection from the sunlight’s damaging ultraviolet rays. Also, vitamin D levels in the blood begin to rise as ultraviolet light strikes the skin, causing it to convert cholesterol into vitamin D.

Vitamin D is a potent inhibitor of the cancer-causing process. In fact, vitamin D has been shown to prevent the growth of melanomas in experimental animals and cultured tissue lines.

An unexpected bonus of vitamin D is that it may also be one of our most important allies in the war against prostate, breast, and colon cancers. Evidence from population studies confirms that people with the greatest lifetime sun exposures have the lowest rates of these cancers.

Skin cancer is a complex disease, with several factors influencing its ultimate course. In laboratory animals, scientists have found that excessive omega 6 fats promote the development of skin cancer—but omega 3 fats slow it down. Furthermore, antioxidants like beta-carotene, vitamin C, and vitamin E tend to prevent the sun’s ultraviolet damage to the skin. You can get these same dietary advantages when you adopt the dietary principles I have laid out in the Paleo Diet. (Note: As with many of the diseases we have discussed, proper diet reduces your risk of developing some types of skin cancer, but it cannot completely prevent it.)

Exposure to sunlight is natural for human beings. It is part of our evolutionary heritage. Without sunlight, it is virtually impossible to achieve an adequate intake of vitamin D from the natural foods that were available to our hunter-gatherer ancestors. Our food supply has been a significant source of vitamin D for a very short time—less than a century, when dairy producers began adding it to milk and, later, margarine. Sunlight exposure is healthy as long as it occurs in a slow, gradual, and limited dose over the course of a lifetime.

As you have seen, the Paleo Diet will not only help you get thin; it will also help prevent and treat a broad range of diseases. The Paleo Diet is good medicine!

Now that I’ve talked about why the Paleo Diet is the diet nature intended, let’s get down to specifics: how do you get started?

This is the best part—it’s so easy. You don’t have to balance food blocks, weigh portions, keep a food log, or count calories. As I’ve shown, the basic guidelines of the Paleo Diet are very simple : all the lean meats, poultry, fish, seafood, fruits (except dried fruits), and vegetables (except starchy tubers—primarily, potatoes) you can eat. Because the mainstay of the Paleo Diet is high-quality, low-fat protein, you won’t need to feel guilty about eating lean meat, fish, or seafood at every meal. This is exactly what you
should
be doing, along with as many low-glycemic fruits and veggies as you want.

You’re about to embark on a diet of enormous and bountiful diversity, fully backed by thousands of clinical nutrition trials and—most important—by 2.5 million years of evolutionary experience. What do you get in return? If you follow the simple nutritional guidelines laid out in this chapter and spelled out in the next two chapters with tempting meal plans and delicious, easy recipes, you will lose weight; reduce your risk of heart disease, cancer, diabetes, and other chronic diseases; and feel energized all day long. And unlike with almost every other diet you can think of,
you won’t feel hungry all the time.
You will feel good on this diet,
because this is the only diet that is consistent with your genetic makeup.

By imitating the diets of our Paleolithic ancestors with foods you can buy at the supermarket or grow in your own garden, you’ll be able to reap the health benefits that are your genetic heritage—freedom from obesity, a high energy level, and excellent health.

It is not possible for us to duplicate precisely all the foods that our ancient ancestors ate. Many of these foods no longer exist—such as the mammoth—or they’re unavailable commercially, or they just aren’t palatable, given our modern tastes and cultural traditions. However, most of the advantages and benefits of the Paleo Diet can easily be obtained from common foods following the general nutritional guidelines observed by our Paleolithic ancestors.

It isn’t easy to change the habits of a lifetime, and you don’t have to do it overnight. You can ease the transition by adopting the three levels of the Paleo Diet. The levels are based on the concept that what you do occasionally won’t harm the overall good of what you do most of the time. Does this mean you can cheat? Yes—sometimes. Occasional cheating and digressions may be just what you need to help you stick to the diet the rest of the time, and they won’t sidetrack the weight loss and health effects of this diet.

As I discussed earlier, there was no single Paleo diet. Our ancient ancestors made the most of their environment wherever they happened to be. For example, the Inuit people were able to live healthy lives, free of chronic diseases, on a diet that derived at least 97 percent of its energy from animal foods. At the other end of the spectrum were groups like the !Kung in Africa, who obtained 65 percent of their daily calories from plant foods (chiefly the mongongo nut). However, most Paleolithic groups fell somewhere in between, with animal foods generally making up around 55-60 percent of the daily caloric intake. On the Paleo Diet, you should attempt to get a little more than half of your calories from lean meat, organ meats, fish, shellfish, and poultry and the rest from plant foods.

Let’s take a look at the wonderful, diverse foods that you can eat in unlimited quantities.

The key word here is “lean.” Of course, this includes chicken and fish. But many people are surprised to find that red meat—beef and pork—organ meats, and game meats are also on the list. How can this be? Because, as I discussed earlier,
the Paleo Diet is not a fat-free diet, it’s a bad fat-free diet.
As long as the meat is lean, you can eat your fill. Another noteworthy aspect of the meats available on this diet is their great variety. This is a common response as people begin this diet: “I was in a rut before—hamburgers, hot dogs, and pizza. Now I’m planning my meals around all kinds of meats—some I had never tried before, some I’d never even heard of.”

In order to get enough protein and calories, you should eat animal food at almost every meal. You can’t just eat animal food, however. You must eat fruits and vegetables, too. Here’s why: if protein-dense, extremely lean meats and seafood are your main sources of calories, you will get sick—with nausea, diarrhea, and weakness—because your body can’t handle this much undiluted protein without something else, either fat or carbohydrates. As we discussed earlier, early Arctic explorers, trappers, and frontiersmen who had no choice but to eat the fat-depleted meat of game animals in the dregs of winter rapidly developed these same symptoms, frequently referred to as “rabbit starvation” or protein toxicity.

The problem, as shown in Dr. Daniel Rudman’s laboratory at Emory University in Atlanta, is that the liver can’t effectively eliminate the nitrogen caused by the protein overload. For most people, the dietary protein ceiling is 200 to 300 grams a day, or about 30 to 40 percent of the normal daily caloric intake.

On the other hand, eating too many fatty meats can wipe out any health benefits that eating high levels of protein will help you achieve. Paleolithic people couldn’t eat fatty meats if they tried—they had nothing like the tubby grain-fed animals that produce our steaks today. Wild game meat contains about 15 to 20 percent of its calories as fat. A lean cut of beef trimmed of all visible fat contains more than double this amount (35 to 40 percent fat). And certain fatty cuts of meats may contain 65 to 80 percent fat.