Excerpted from The Paleo Diet for Athletes: A Nu¬tritional Formula for Peak Athletic Performance by Loren Cordain, Ph.D, and Joe Friel, M.S.

Chapter 9: The 21st-Century Paleo Diet: Special Dietary Needs of Modern Athletes

As a serious athlete, you have a lifestyle and activity level that are far different from that of the average American. Chances are your training patterns also vary sig¬nificantly from the daily activ¬ity patterns of our Paleolithic ancestors. They were unlikely to ever run 26.2 miles as fast as they could, non¬stop. Nor would they work and run at high-in¬tensity levels day after day, week after week. The only rea¬son for doing so would be under extreme condi¬tions in which their lives were continually at risk, and the only way to sur¬vive would be to run far and fast every day. Such situations would be rare. As you will see in the next chapter, the more typical man¬ner of “exercise” for the Paleolithic athlete would have involved long, steady hunts and foraging expeditions conducted at a moder¬ate pace until the kill was imminent or the gathered foods were hauled back to camp. At these times their effort would increase, but they would no doubt rest at every op¬portunity. Ceremonial dance would also provide nearly continuous “exercise,” but the intensity would be relatively low.

What all of this means for you is that your diet must be modified slightly to accommodate your “unusual” high-level train¬ing patterns that are a requisite for peak perfor¬mance during competition. These modifica¬tions, as you are now well aware, involve exactly when and what you eat before, during, and im¬mediately fol¬lowing exercise. These critical dietary nuances were discussed extensively in Chapters 2, 3, and 4.

Now let’s get down to the crux of this chapter: What should you eat for the remainder of your day, from the time short-term recov¬ery ends until just before the next workout begins? During this period, you should be eating in a manner similar to that of your Paleolithic ancestors. You’ll quickly discov¬er that your day-to-day recovery is greatly enhanced and, as a result, your performance will improve.

21st-Century Dietary Tweaks

Let’s make it clear from the start: It would be nearly impossible for any athlete or fit¬ness enthusiast living in a typical modern setting to exactly replicate a Paleolithic hunter-gatherer diet. Many of those foods are unavailable commercially, no longer ex¬ist, or are totally disgusting to modern tastes and cultural traditions. Do brains, marrow, tongue, and liver sound appealing to you? Probably not, but to hunter-gatherers, these organs were mouthwatering treats that were gobbled up every time an animal was killed. For hunter-gatherers, the least appetizing part of the carcass was the muscle tissue, which is about the only meat most of us ever eat.

Most of the familiar fruits and veggies that we find in the produce section of our super¬markets bear little resemblance to their wild counterparts. Large, succulent, orange car¬rots of today were nothing more than tiny, purple or yellow, fibrous roots 1,000 years ago. The numerous varieties of juicy, sweet apples that we enjoy would have resembled tiny, bitter crabapples a few thousand years ago. Thanks to thousands of years of selec¬tive breeding, irrigation, and, later, fertil¬izers and pesticides, we now eat domesti¬cated fruits and veggies that are larger and sweeter, and have less fiber and more carbo¬hydrate, than their wild versions. Does this mean that you need to go out and forage for wild plants and animals to stock your pan¬try for our lifetime nutritional plan? Abso¬lutely not! Nearly all of the performance re¬wards and health benefits of the Paleo Diet for Athletes can easily be achieved from modern-day foods and food groups that had a counterpart in Stone Age diets.

The fundamental dietary principle for the Paleo Diet for Athletes is simplicity itself: unrestricted consumption of lean meats, poultry, seafood, fruits, and vegetables. Foods that are not part of the modern-day Paleolithic fare include cereal grains, dairy products, high glycemic fruits and vegeta¬bles, legumes, alcohol, salty foods, high fat meats, refined sugars, and nearly all pro¬cessed foods.

The exceptions to these basic rules were fully outlined in Chapters 2, 3, and 4. For instance, immediately before, during, and after a workout or competition, certain non-optimal foods may be eaten to encourage a quick recovery. During all other times, meals that closely follow the 21st-century Paleolithic diet described here will promote comprehensive long-term recovery and al¬low you to come within reach of your maxi¬mum performance potential.

Animal and Plant Food Balance

A crucial aspect of the 21st-century Paleo¬lithic diet is the proper balance of plant and animal foods. How much plant food and how much animal food were normally consumed in the diets of Stone Age hunter-gatherers? There is little doubt that when¬ever and wherever it was ecologically pos¬sible, hunter-gatherers preferred animal food over plant food. In our recent study of 229 hunter-gatherer societies, published in the American Journal of Clinical Nutrition, my research team showed that 73 percent of these cultures obtained between 56 and 65 percent of their daily subsistence from ani¬mal foods. In a follow-up study published in the European Journal of Clinical Nutri¬tion, involving 13 additional hunter-gath¬erer groups whose diets were more closely analyzed, we found almost identical results. Our colleague, Mike Richards, PhD, of the University of Bradford in the United King¬ dom, has taken a slightly different approach in determining the plant-to-animal balance in Stone Age diets. He has measured chem¬icals called stable isotopes in skeletons of hunter-gatherers that lived during the Pa¬leolithic Era. His results dovetailed nicely with ours and confirmed that hunter-gather¬ers living 12,000 to 28,000 years ago were no different from contemporary hunter-gather¬ers—the majority of their daily calories also came from animal sources.

Based upon the best available evidence, you should try to eat a little more than half (50 to 55 percent) of your daily calories from lean meats, fish, and seafood. Avoid fatty meats, but fatty fish such as salmon, mackerel, and herring are perfectly accept¬able because of their high concentrations of healthful omega-3 fatty acids and cholester¬ol-lowering monounsaturated fats. Table 9.1 lists some of the animal foods you should include in your diet as well as those you should avoid.

How About Fatty Meats?

Some people who have adopted what they think are “Paleolithic diets” have embraced fatty meats such as bacon, T-bone steaks, and ribs as staples. Even some of the diet doctors with high-fat, low-carbohydrate weight-loss schemes have tried to jump on the Paleolithic bandwagon by suggesting that fatty meats would have been normal fare for Stone Agers. Let’s take a look at the real story.

Because animals had yet to be domesticat¬ed, Stone Age hunters could eat only wild animals whose body fat naturally waxes and wanes with the seasons. In contrast, vir¬tually all of the meat in the typical US diet comes from grain-fattened animals, slaugh¬tered at peak body-fat percentage regard¬less of the time of year. For instance, mod¬ern feedlot operations typically produce an obese (30 percent body fat or greater) 1,200-pound steer ready for slaughter in about 14 months. These animals are produced like clockwork, 12 months a year, no matter whether it is spring, summer, fall, or winter. That’s quite the opposite of wild animals such as caribou, whose body fat changes with the seasons, as shown in Figure 9.1. Note that for 7 months out of the year, total body-fat averages less than 5 percent. Only in the fall and early winter are significant body fat stores present, but these values are one-half to two-thirds less than the obese feedlot-produced steer!

Even more telling is how the types of fat change seasonally in the carcasses of wild animals. Remember, hunter-gatherers rel¬ished all edible body parts--they ate every¬thing except bones, hooves, hide, and horns. By analyzing the total amount of fat and the kinds of fat in muscle, storage fat, and all of the edible organs, our research team was able to show how the animal’s total body content of saturated fat varied with the sea¬sons. Take a look at Figure 9.2 on page 168; you can see that for 7 months out of the year, the saturated fat from the edible carcass av¬erages only 11.1 percent of its total avail¬able calories—meaning that hunter-gather¬ers simply did not have a high, year-round dietary source of saturated fat. To lower our blood cholesterol levels and reduce the risk of heart disease, the American Heart Associ¬ation recommends that our dietary saturat¬ed fat intake be 10 percent of our total daily calories—remarkably close to what hunter-gatherers could have obtained from eating wild animals on a year-round basis! For this reason, we recommend that you always eat the leanest cuts of meat.

There is absolutely no doubt that hunter-gatherers favored the fattiest parts of ani¬mals. There is incredible fossil evidence from Africa, dating back to 2.5 million years ago, showing this scenario to be true. Stone-tool cut marks on the inner jawbone of an¬telope reveal that our ancient ancestors re¬moved the tongue and almost certainly ate it. Other fossils show that Stone Age hunt¬er-gatherers smashed open long bones and skulls of their prey and ate the contents. Not surprisingly, these organs are all relatively high in fat, but, more important, analyses from our laboratories showed the types of fat in the tongue, brain, and marrow are healthful, unlike the high concentrations of saturated fats found in fatty domestic meats. Brain is extremely high in polyunsaturated fats, including the health-promoting omega-3 fatty acids, whereas the dominant fats in tongue and marrow are the cholesterol-low¬ering monounsaturated fats.

Most of us would not savor the thought of eating brains, marrow, tongue, liver, or any other organ meat on a regular basis; there¬fore, a few 21st-century modifications of the original Paleolithic diet are necessary to get the fatty acid balance “right.” First, we suggest you limit your choice of meats to very lean cuts, but don’t worry about fatty fish--they’re good for you, just like the organ meats our ancestors preferred. Second, we recommend that you add healthful vegetable oils to your diet. By following these simple steps, together with the other nuts and bolts of this plan, the fatty acid balance in your diet will approximate what our Stone Age ancestors got.

From our analyses of 229 hunter-gatherer diets and the nutrient content of wild plants and animals, our research team has demon¬strated that the most representative fat in¬take would have varied from 28 to 57 per¬cent of total calories. To reduce risk of heart disease, the American Heart Association recommends limiting total fat to 30 percent or less of daily calories. On the surface, it would appear that, except for the extreme lower range, there would be too much fat in the typical hunter-gatherer diet--at least according to what we (the American pub¬lic) have heard for decades: Get the fat out of your diet! The Food Pyramid cautions us to cut out as much fat as possible and re¬place it with grains and carbohydrate. Not only is this message misguided, it is flat-out wrong. Scientists have known for more than 50 years that it is not the total amount of fat in the diet that promotes heart disease but, rather, the kind of fat. Plain and simple, it is a qualitative issue, not a quantitative one! Polyunsaturated fats are good for us, partic¬ularly when we correctly balance the ome¬ga-3 and omega-6 fatty acids. Monounsatu¬rated fats are heart-healthy, and even some saturated fats such as stearic acid (found in animal fat) do not promote heart disease. Deadly fats are three specific saturated fats (palmitic acid, lauric acid, and myristic acid) and the trans fats found in margarine, shortening, and hydrogenated vegetable oils, as well as processed foods made with these products.

Now let’s get back to the fat content of our ancestral hunter-gatherer diet. They frequently ate more fat than we do, but it was almost invariably healthy fats. Using computerized dietary analyses of the wild plant and animal foods, our research team has shown that the usual fat breakdown in hunter-gatherer diets was 55 to 65 percent monounsaturated fat, 20 to 25 percent poly¬unsaturated fat (with an omega-6-to-omega-3 ratio of 2:1), and 10 to 15 percent satu¬rated fat (about half being the neutral stearic acid). This balance of fats is exactly what you will get when you follow our dietary recommendations.

Foods Not on the Paleolithic Menu

Let’s get down to the specifics of the diet. Table 9.2 on page 172 includes an inven¬tory of modern foods that should be avoid¬ed. These recommendations might at first seem like a huge laundry list, with seem¬ingly needless elimination of entire food groups. Most dyed-in-the-wool nutritionists wouldn’t object to our advice to cut down or eliminate sugars and highly refined, pro¬cessed foods. They would have no problem with our suggestions to reduce saturated and trans fats and salt, and they would be ec¬static about our recommendations to boost fresh fruit and vegetable consumption. But they would, guaranteed, react violently to the mere thought of eliminating “sacred” whole grains from your diet. If they heard we also advocate reducing or eliminating dairy products, they almost certainly would brand this diet unhealthful, if not outright dangerous. You may wonder why, just be¬cause hunter-gatherers did not regularly eat grains or dairy products, you should follow suit. After all, aren’t whole grains healthful, and isn’t milk good for everybody? How can you get calcium without dairy? And won’t eating a lot of meat increase blood choles¬terol levels?

In science, decisions should be made based upon what the data tell us, and not upon hu¬man bias and prejudice. With these ground rules in mind, let’s take a look at the reasons for and potential benefits of eliminating or severely restricting entire food groups with the Paleo Diet for Athletes. One of the major goals of any diet, for both athletes and non-athletes alike, is to supply you, the consum¬er, with a diet rich in nutrients (vitamins, minerals, and phytochemicals) that promote good health, which in turn promotes good performance. Table 9.3 on page 174 shows the nutrient density of seven foods groups.

From top to bottom, here’s the ranking of the most nutritious food groups: fresh vegeta¬bles, seafood, lean meats, fresh fruits, whole grains and milk (tied for second to last), and nuts and seeds. Why in the world would the USDA place grains at the Pyramid’s base if the goal is an adequate intake of vitamins and minerals? This strategy makes no sense for the average American, much less athletes like you. Had we included refined grains in the list, they would have ended up dead last because the refining process strips this nutrient-poor food group even further of vi¬tamins and minerals. Unfortunately, in the United States, 85 percent of the grains we eat are highly refined, and grains typically make up 24 percent of our daily calories.

Not only are grains and dairy foods poor sources of vitamins and minerals, they also retain nutritional characteristics that clearly are not in your best interest, whether you’re an athlete or not. From Chapter 5, you now know all about the glycemic index and acid/base balance in foods, along with how they impact your performance. Virtually all refined grains and grain products yield high glycemic loads. Further, all grains, wheth¬er whole or refined, are net acid produc¬ing. Dairy products are one of the greatest sources of artery-clogging saturated fats in the American diet, and cheeses produce the highest acidic loads of any foods. If that’s not bad enough, a recent study found that dairy products, despite having low glycemic indices, spike blood insulin levels similar to white bread. Do yourself a favor—get the grains and dairy out of your diet and replace them with more healthful fruits, veggies, lean meats, and seafood.

If you, like most Americans, have been swayed by those milk mustache ads, you probably are part of the mass hysteria, large¬ly generated by the dairy industry, suggest¬ing there is a nationwide calcium shortage that underlies osteoporosis. Not true! Cal¬cium intake from dairy, or any other food, is only part of the story behind bone mineral health. More important is calcium balance, the difference between how much calcium goes into your body from diet and how much leaves in urine. You will be out of balance if more calcium leaves than what comes in, no matter how much milk you drink. What we really need to pay attention to is the other side of the equation—the calcium leaving our bodies. Dietary acid/base balance is the single most important factor influencing cal¬cium loss in the urine. Net acid-producing diets overloaded with grains, cheeses, and salty processed foods increase urinary cal¬cium losses, whereas the Paleo Diet for Ath¬letes is rich in alkaline-yielding fruit and vegetables that bring us back into calcium balance and promote bone mineral health.

Dietary Staples: Lean Meats

With the Paleo Diet for Athletes, you’ll be eating lean meat and seafood, and lots of it, at almost every meal. Should you be wor¬ried about your blood cholesterol levels ris¬ing? Absolutely not, and here’s why. In the 1950s, when scientists began to realize that saturated fats promote heart disease, a na¬tionwide campaign was initiated to reduce dietary fats, and meat became a primary tar¬get. As this strategy gained momentum in the late ’60s and early ’70s, meat, and red meat in particular, became vilified. In the eyes of overzealous vegetarians, nutrition¬ists, and physicians, meat consumption was the scapegoat underlying the epidemic of heart disease and cancer in the United States. But the problem was oversimpli¬fied—they threw out the baby with the bath¬water. It was not meat, per se, that was the problem; rather, it was the fatty meats such as hamburger, T-bone steaks, bologna, and hot dogs that had become the norm in the US diet.

This fact was strikingly demonstrated by my colleague, Andy Sinclair, PhD, from the Royal Melbourne Institute of Technology, with a clever dietary intervention in which people were fed a diet either of lean beef trimmed of visible fat or with the trimmed fat added back in. When lean beef was con¬sumed, LDL (bad) cholesterol in the blood declined, but (not surprisingly) it increased when the fat was added back in. These re¬sults have been duplicated numerous times in independent labs. In fact, experiments by Bernard Wolfe, MD, at the University of Western Ontario have decisively shown that when low-fat animal protein replaces dietary saturated fat, it is more effective in lowering blood cholesterol and improving blood chemistry than are low-fat carbohy¬drates. In nutritional interventions such as Dr. Wolfe’s, the key to scientific credibility is replication—replication, replication, rep¬lication! It is absolutely essential that other scientists get similar results from compa¬rable experiments. To the surprise of some party-line nutritionists, a series of four re¬cent (2003) papers from independent re¬searchers around the world confirmed Dr. Wolfe’s earlier work.

Is there a limit to a good thing? You now know that lean animal protein lowers your blood LDL (bad) cholesterol levels, increas¬es HDL (good), and provides muscle-build¬ing branched-chain amino acids. How much protein should—or can—you eat?

There is a limit to the amount of protein you can physiologically tolerate. Nineteenth- and 20th-century explorers, frontiersmen, and trappers who were forced to eat noth¬ing but the fat-drained flesh of wild game in late winter or early spring developed nau¬sea, diarrhea, and lethargy, and eventually died. Studies conducted in the laboratory of Daniel Rudman, MD, at Emory University have examined the causal mechanisms un¬derlying the protein ceiling and found that toxicity occurs when the liver can’t elimi¬nate nitrogen from the ingested protein fast enough. Nitrogen is normally excreted as urea in the urine and feces, but with pro¬tein toxicity, ammonia and excessive amino acids from protein degradation build up in the bloodstream and produce adverse symptoms. For most people, the maximum dietary protein limit is between 200 and 300 grams per day, or about 30 to 40 percent of the normal daily caloric intake. On the Pa¬leo Diet for Athletes, you will never have to worry about protein toxicity, as you will eat unlimited amounts of carbohydrates in the form of fruits and vegetables. Further, in the post-exercise window, as fully explained in Chapters 2, 3, and 4, you will be encouraged to consume high glycemic, alkaline-yield¬ing carbohydrates to fully replenish your glycogen stores.

From our analyses of hunter-gatherer diets and the nutrient content of wild plants and animals, our research team has shown that the protein intake in the average hunter-gatherer diet would have ranged from 19 to 35 percent of daily calories. Since the pro¬tein intake in the normal US diet is about 15 percent of daily energy, we recommend that for peak performance during Stage V of re¬ covery (the period following short-term re¬covery, lasting until your next pre-exercise feeding), you boost your protein intake to between 25 and 30 percent of daily calories. At values higher than 30 percent of energy, some people may begin to experience symp¬toms indicative of the physiologic protein ceiling.

Macronutrient Balance

We’ve already mentioned that the fat con¬tent in Paleolithic diets (28 to 57 percent total calories) was quite a bit higher than values (30 percent or less) recommended by the American Heart Association. We sug¬gest consuming between 30 and 40 percent of your Stage V energy as fat. But remem¬ber, you will be eating the bulk of your fats as healthful monounsaturated and polyun¬saturated fats (particularly the omega-3s). How about carbohydrates? In hunter-gath¬erer diets, carbohydrate normally ranged from 22 to 40 percent of total daily energy. Because of your special need as an athlete to restore muscle glycogen on a daily basis, you should boost these values a bit higher. We suggest that Stage V carbohydrate intake should typically range from 35 to 45 percent of calories. As you personalize the Paleo Diet for Athletes to your specific training sched¬ule and body needs, you will be able to fine-tune your daily intake of carbohydrate, fat, and protein.

Nutritional Adequacy

Regardless of your final ratio of protein to fat to carbohydrate, you will be eating an enor¬mously enriched and nutrient-dense diet, compared with what you were probably eat¬ing before. We’ve partially addressed this concept in Chapter 1, where we compared the Paleo Diet for Athletes with the recom¬mended USDA food pyramid diet, and also in Table 9.3 on page 174. An even better way to appreciate how much more nutritious your diet will become when you adopt the Paleo Diet for Athletes is by looking at what the average American eats. Figure 9.3 shows the breakdown by food group in the typical US diet. Notice that grains are the highest contributor to total calories (23.9 percent), followed by refined sugars (18.6 percent) and refined vegetable oils (17.8 percent). When you add in dairy products (10.6 per¬cent of total energy) to grains, refined sug¬ars, and refined oils, the total is 70.9 percent of daily calories. None of these foods would have been on the menu for our Paleolithic ancestors, as fully discussed in Chapter 8.

Refined sugars are devoid of any vitamins or minerals, and except for vitamins E and K, refined vegetable oils are in the same boat. Think of it: More than a third of your daily calories come from foods that lack virtu¬ally any vitamins and minerals. When you add in the nutrient lightweights we call ce¬reals and dairy products (check out Table 9.3 on page 174), you can see just how bad the modern diet really is. The staple foods (grains, dairy, refined sugars, and oils) intro¬duced during the agricultural and industrial revolutions have displaced more healthful and nutrient-dense lean meats, seafood, and fresh fruits and vegetables. Once you begin to get these delicious foods back into your diet, not only will your vitamin, mineral, and phytochemical intake improve, but so will your performance.

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