Marathon Training Academy

Marathon Training Academy


Going Beyond Training to Master Your Fitness - Interview with Ben Greenfield

February 21, 2014


Ben Greenfield participating in a high fat low carb performance study


In this episode we talk with nutrition expert and triathlete Ben Greenfield about going beyond training to master your endurance.


Ben talks with us about being a fat adapted runner and answers nutrition questions from the listening audience.


You will hear questions and answers about his new book Beyond Training, the benefit of fat adaption for endurance athletes, the best way to become fat-adapted, what to do about an under active thyroid, snacks that fill you up without causing weight gain, what type of diet his kids eat, preventing heart & coronary disease, and the question of whether supplements provide a clear benefit.


But Wait There’s More!

We got exclusive permission to post content from chapter 13 of Beyond Training -the chapter entitled “How Much Carbohydrate, Protein, and Fat You Need to Stay Lean, Stay Sexy, and Perform Like a Beast”.


I asked him for this chapter because it deals specifically with high fat low-carb diets. As far as I know, we are the only website on the internet where you can read this content for free! (yes, we feel special)

How Much Carbohydrate, Protein, and Fat You Need to Stay Lean, Stay Sexy, and Perform Like a Beast

By Ben Greenfield


In this chapter, I’m going to give you three reasons calories don’t really matter, and tell you how much carbohydrate, protein, and fat you need to stay lean, stay sexy, and perform like a beast—and also get a sample week of eating to support ideal levels of performance, endurance, and exercise.


Three Reasons Calories Don’t Really Matter

Earlier, you learned how to count your calories and log your diet. But it’s important to realize that it’s the nutrient density and quality of your food that truly matters—not the calorie content.


But wait—a calorie is a calorie, right? Not really.


In the most recent such study (26), one group ate slow-sugar-release, low-glycemic-index foods (think raw nuts or beef jerky), and another group ate faster release, high-glycemic-index foods (think white rice or wheat bread). But both groups ate identical amounts of calories.


Researchers then monitored blood-sugar levels and appetites of the subjects, and found that those consuming the high-glycemic-index foods had a blood-sugar-level crash just a few hours after eating, and were hungrier sooner than those who ate the slower release foods. In other words, an identical amount of calories consumed from a sweeter food triggered food-addiction symptoms and hunger cravings.


If you want to read a great book about why calories matter much less than we think, I recommend Good Calories, Bad Calories, by Gary Taubes. But just in case you don’t have the time or inclination to read a whole book on the subject, I’ll give you three quick reasons that your primary focus should not be on counting calories.


1. Humans Don’t “Burn Calories.â€

Calories technically don’t even exist. A calorie is just a unit of measurement used to describe the amount of heat produced when a nutrient is burned in a metal oven called a calorimeter. And your body is much, much different than a simple metal oven. The process of burning fat or turning nutrients into energy or stored matter is way more complex than counting fictitious calories—and as you’ve learned from the study above, something as subtle as the difference in the speed of sugar release can result in significantly different hormonal and metabolic reactions to a food.


2. Calories Aren’t Our Fuel for Exercise.

Human motion is not fueled by calories. It’s fueled by the nutrient-derived chemical adenosine triphosphate (ATP). The problem with relying on counting calories—besides the nonexistence of calories—is that it somehow makes us believe that our bodies are using exactly what we ate before the workout for fuel. In reality, your own storage fat provides the most concentrated source of energy—and there are athletes (you can find them at RunKeto.com or on Jack Kruse’s forum at jackkruse.com) who are exercising at a steady state for entire days with no actual calorie intake. Their bodies are producing ATP from fat stores.


3. Nutrients Are What Really Matter.

In reality, nutrients matter far more than calories, and nowhere is this more true than in exercising individuals. When the focus is on calories, everything becomes about the numbers rather than the nutrition—and you can easily end up missing key vitamins and minerals.


For example, a highly processed (but relatively nutrient-empty) Tacquitos snack pack advertised as just 100 calories seems like a real deal if you’re counting calories. But in choosing the snack pack, you might pass on a calorically equivalent large apple that rings in at roughly the same amount of calories. The apple delivers vitamin C, folate, fiber, potassium, vitamin B6, thiamin, and riboflavin, while the chips deliver vegetable oils, preservatives, and starch.


So the apple beats the Tacquitos. And incidentally, 100 calories of wild salmon beats the apple. And (although you may not like to hear this), 100 calories of organic, grass-fed liver beats the wild salmon.


Where to Start

Great Ben, I’ve got a bunch of nutrient-dense meals I can turn to now.

I’m following the rules. I’m not incessantly counting calories. I’m paying more attention to the way I look, feel, and perform than to scales and numbers. I’m paying more attention to nutrients than to calories.


But how do I know how much carbohydrate, protein, and fat I should actually be eating to fuel my active lifestyle, without destroying my body in the process?


Definitely don’t start with the traditional food pyramid.


Remember this? The USDA Food Pyramid created in 1992


Since 1974, when the first food pyramid appeared in Sweden, triangular- or pyramid-shaped nutrition guides have been used worldwide. There is a great graphic on the Huffington Post (which I’ll link to in the webpage for this chapter) that depicts some of the more popular food pyramids from around the world. Although in 2011, the USDA Food Pyramid was replaced with the new MyPlate design (see ChooseMyPlate.gov), it is very similar to the old food pyramid in terms of nutrient percentages, and many countries still use a traditional food pyramid to dispense nutrition advice.


Interestingly, in food pyramids around the globe, from China’s “food pagoda†to Greece’s food pyramid, cereals, grains, bread, pasta, and other starchy carbohydrates consistently form the base of the diet—with fats near the top of the pyramid, as a “use sparingly†category.


But this type of nutritional advice can lead to some serious health problems. After all, dietary fat from healthy sources has been shown to actually help to increase weight loss, reduce risk of heart disease, lower blood sugars, lower damaging forms of cholesterol, and maintain proper brain function, especially in kids (34).


And if you listen to the interview on my website with Dr. William Davis, “The Shocking Truth about Wheat,†or my interview with Paul Jaminet about his Perfect Health Diet, you will learn that consumption of carbohydrates can cause everything from weight gain to fuzzy thinking to heart disease.


But the issues don’t stop with the predominantly high-carb, low-fat endorsements of most food pyramids. Frequent consumption of recommended foods such as pasteurized whole milk and hamburger has been linked to heart disease, not to mention that:


Dairy is extremely overemphasized—although calcium is important, many vegetable and meat sources contain plenty of calcium with fewer calories.


There is no difference between “good proteins†and “bad proteins,†“good carbs†and “bad carbs,†or “good fats†and “bad fats.â€


The minimum daily serving of fruits is two to four, and that much fruit is a great way to send your blood-sugar levels on a roller-coaster ride all day long if you’re not careful.


Furthermore, at least when it comes to the USDA food recommendations, we’ve barely acknowledged the lobbying and political power of Big Food and Big Agra to subsidize industries such as dairy, corn, and wheat and heavily promote their products. (A great book to read more about these shenanigans is Food Politics, by Marion Nestle.)


So What Should a Good Food Pyramid Actually Look Like for an Athlete?

Ben Greenfield’s Super Human Food Pyramid


Although I have yet to be convinced that a food pyramid is the best, most functional way to dynamically depict dietary recommendations, a couple of years ago I acted on hundreds of requests from readers and listeners and created a “Ben Greenfield–endorsed†food pyramid that is rich in the best nutrient-dense foods to support an active lifestyle.


I call this design the Superhuman Food Pyramid, and it address all the issues above, ties in my personal nutritional philosophies, and also gives you a spectrum of choices from “Eat†to “Moderate†to “Avoid†for each food group, so you don’t have to deal with, for example, “Fats†lumped into just one category or “Proteins†lumped into only one, either.


To make it easier to put the Superhuman Food Pyramid into practice, I’ve also included several pages listing each food category and the “Eat,†“Moderate,†and “Avoid†foods within that category, so you can print, grab, and go to the grocery store or farmers’ market with your Superhuman Food list.

The Superhuman Food Pyramid is free (and you can listen to me expounding on why “Fat Is Goodâ€).


How Many Carbohydrates Should an Active Person Eat?

ben_greenfield_spartan_raceNow that you’ve got a supply of meals, a good way to choose nutrient-dense foods, and a handy grocery-shopping list, it’s time to dig into how many carbohydrates you should actually eat.


After all, isn’t the answer to “How much carbohydrate?†the Holy Grail of fueling for athletes?


First, I’ll readily admit it: I’m known as the low-carb, high-intensity guy. Based on what you’ve learned so far in this book, that’s probably no surprise—train hard, eat healthy, don’t stuff your face with too much sugar.


After living on a high-carb, junk-food diet and then switching to the high-protein, low-fat, low-carb diet you read about in chapter 1,the introduction to this book, I’ve followed the Paleo diet, a vegan diet, an Atkins diet, and even a ketogenic diet, and the one prevailing characteristic that defines how good or how bad I feel is the amount of sugar and refined carbohydrates I eat, regardless of diet protocol.


My own experience with a low-carbohydrate diet began with an attempt to lose extra holiday pounds, followed by the stark realization that, contrary to my expectations and what I had been taught in traditional sports-nutrition classes, my performance, focus, and energy levels actually improved despite a lower carbohydrate intake. That was when I personally started digging into this stuff.


Turns out, it’s not just me.


Every month, I gaze at dozens of lab results of clients, and the same pattern pops up over and over again—the higher the sugar and starch intake, the higher the blood triglycerides, the greater the inflammation, the worse the sleep, the more difficulty controlling body-fat levels, and so on. Once the relatively nutrient-void carbohydrate sources—energy bars, whole-wheat bread, granola, cereal, meusli, pasta—are replaced with more nutrient-dense and healthy fats, proteins, and vegetables, biomarkers and performance quickly begin to take a turn for the good. Of course, there are other nutrient-empty foods that we also cut, like vegetable oils, egg whites without the yolks, industrialized beef, and chicken and commercial dairy— but, especially for athletes, carbohydrates are the biggie.


This is because what I’ve discovered, and what you’re about to learn, is that maintaining high blood sugar and constantly “topping off†storage carbohydrate levels to fuel your body for optimum performance may not actually be worth the health trade-off—especially if you can get the same results by eating less starch and sugar. There are proven health and longevity benefits to controlling high blood sugar, and I don’t know about you, but if I can get those benefits and still maintain performance, I’m all in.


But (shocker!), I still do not recommend a low-carbohydrate diet for everyone, and I usually do not recommend it blindly for:



  1. Athletes in the heat of competition. During, say, an Ironman triathlon, you need a higher carbohydrate intake than on an easy training day. Duh. If you’re going to go destroy yourself for nine to seventeen hours, you may need some extra glucose onboard. Interestingly, research suggests that this may be more because of a need to stave off neural fatigue than a direct carbohydrate need by the actual muscles (19). But more on that in the chapter on a healthy race-day nutrition plan. For now, just realize that may you need extra carbs if you’re going deep into the pain cave.
  2. Athletes doing an extremely heavy block of training that is higher-load than they are accustomed to, such as a triathlon camp that involves twenty-five to forty hours of hard work a week. In this case, you usually need more carbohydrates. I’m not saying that this volume of training and carbohydrate intake are healthy, but in some cases it can be a necessary sacrifice for building endurance in a big way. In other words, if you’re going to ask your body to do a crap-ton of unnaturally heavy work, at least give it some sweet potato fries or an extra helping of white rice.
  3. Individuals with diseases or conditions that prevent them from properly metabolizing fats and proteins. For example, if you’ve had your gallbladder removed, a high-fat diet full of Kerrygold butter, coconut oil, and bacon may not sit so well in your gut.

However, if you’re an average athlete putting in an average amount of training (that is, you are following the ancestral-athlete rules you learned about earlier), you need far fewer carbohydrates than what is widely recommended. There are three primary reasons for this.



  1. Eating fewer carbohydrates can help you get lean or stay lean. A key component of weight loss is tapping into storage fat (adipose tissue) for energy. This access to fat cannot happen if the body is constantly drawing on carbohydrate reserves and blood glucose for energy (20). In a moderate- to high-carbohydrate diet, not only does the utilization of fat for energy become far less crucial, but the body never becomes ideally efficient at using fat.There is a growing body of evidence proving that a high-fat, low-carbohydrate diet results in faster and more permanent weight loss than a low-fat diet. Furthermore, appetite satiety and dietary satisfaction are significantly improved with a high-fat, low-carbohydrate diet that includes moderate protein.
  2. Eating fewer carbohydrates can increase health and longevity.

    When glucose is used for energy, a lot of free radicals are produced. Free radicals are dangerous molecules that can damage normal cellular processes (9). The burning of fat for energy does not create this same cellular damage. For an athlete who is already generating significant numbers of free radicals from exercise, further damage from high-blood-glucose levels becomes a double whammy. In addition, the constantly elevated levels of circulating blood sugars that can be caused by a moderate- to high-carbohydrate diet are associated with nerve damage; small, dense cholesterol particles (the culprits in heart disease); high morbidity; bacterial infection; cancer progression; and Alzheimer’s.

    As you will learn later in this chapter, simply getting your energy from non-blood-glucose-based energy sources can directly improve your quality of life and ensure that you live longer and healthier.


  3. Eating fewer carbohydrates can increase energy stability and eliminate gastrointestinal distress while training or racing. Because of genetic predispositions, some athletes are much more sensitive to the fluctuations in blood sugar caused by carbohydrate intake (13). Oftentimes, when these athletes consume a sports bar, drink, gel, or other carbohydrate source, after the short-lived initial increase in energy levels, this sensitivity prompts a sharp and drastic drop in energy. But the calories from fats and proteins are utilized at a far more steady rate than carbohydrate sugar, resulting in more stabilized energy levels.In addition, uncomfortable amounts of gas and bloating can be a result of the high bacterial activity caused by carbohydrate fermentation in the digestive tract. Many athletes experience an even greater degree of gastrointestinal distress from food allergies or intolerances to common carbohydrate sources, particularly wheat.

But, Wait! Don’t I Need Carbohydrates to Fuel Training?

carbsAh . . . the million-dollar question. Here’s the thing: If you eat mostly carbs, your body will run on mostly carbs. If you eat mostly fat, your body will run on mostly fat.


But despite your very cool ability to change the fuel you burn depending on what you eat, carbohydrates are consistently the darling of most modern sports-nutrition advice gurus. The standard recommendation to athletes engaging in regular training and racing, especially in endurance sports or extremely demanding exercise, is to consume seven to ten grams of carbohydrate per kilogram of body weight daily for optimal performance, and to consume large amounts of sugary drinks, gels, and bars during prolonged activity to keep blood glucose elevated. And many carbohydrate-loading protocols call for up to 85 percent carbohydrate intake in those last few days before a big workout or event. Talk about keeping cereal companies in business!


In other words, the Holy Grail seems to be to protect carbohydrate stores at all times. The general argument for carbohydrate consumption goes something like this:



  • Fatigue during training and racing is thought to coincide with the carbohydrate fuel tank approaching empty (the infamous bonk).
  • Because it is thought that you can’t burn fat as a primary fuel at training and racing intensities, all focus is on looking for ways to increase the size of the carbohydrate fuel tank (despite even the leanest of athletes having tens of thousands of calories of readily accessible storage fat).
  • This entire process is partly driven by the cheapness of carbohydrate sources—hello, government subsidizing of grains and carbs!—and a mistaken belief that eating a lot of fat, no matter how healthy, may have deleterious health effects.

So, based on this advice, you roll out of bed and glance at your watch. You’ve got a twelve-mile run or some other big workout on tap for the day, and limited time to get it in. Do you lace up and head out without grabbing a banana, bagel, or fistful of sports gels, or . . . do you make sure you have some valuable sugar to consume before and during your effort, so you don’t “bonkâ€? If you’re a good little athlete who heeds popular nutrition “wisdom,†you probably raised your hand and said, “Eat sugar!â€


Now, there is absolutely no arguing with the fact that high-carbohydrate intake before an endurance workout can postpone fatigue and improve performance. So there is some logic to the recommendation from most sports nutritionists to consume a diet that provides high-carbohydrate availability before and during exercise.


But when it comes to finding the ideal combination of both performance and health, I have another question for you: How superior is high-carbohydrate intake to the polar opposite—high-fat, low-carbohydrate intake?


Turns out, there is a lot about this stuff in the scientific literature.



A study published in Medicine & Science in Sports & Exercise in 2010 suggested the answer to this question when the authors coined the phrase train low, compete high in response to results that showed untrained individuals achieving better training adaptations and aerobic capacity after ten weeks of training on a low-carbohydrate diet, compared with subjects who had high-carbohydrate intake before and during exercise (21).Another study, in the Journal of Applied Physiology, showed that trained individuals who performed twice-a-day sessions without eating for two hours after the first session (thus depleting carbohydrate stores with the first session) experienced a better ability to store carbohydrate, use carbohydrate as energy, and burn fat—with no loss in performance—compared with a group that trained only once a day and ate carbohydrates afterward (23).A study of trained cyclists doing high-intensity-interval training with no carbohydrate intake showed improved fat utilization and an increase in the enzymes involved in energy metabolism—again, with no loss of performance (28).Additional research shows that when carbohydrate stores are depleted by almost 50 percent, there is actually increased stimulus for enhanced enzyme activity in skeletal muscle, which is a good thing, since it means you can more efficiently produce energy from fuel (32).You can also read:

The Art and Science of Low Carbohydrate Performance, by Jeff Volek and Stephen Phinney. “High Fat Diets & Endurance Exercise Performance,†a really good article by a Norwegian exercise scientist which I’ll link to in the web page for this chapter. An excellent series of articles called “High Fat Diet for Cyclists†by Jamie Scott at thatpaleoguy.com. But don’t worry, the articles are great for more than just cyclists.


Faster Recovery

And guess what else? This one shocked me when I first realized it, but eating fewer carbohydrates during a workout can actually help you recover faster.


How? Without delving too deeply into the nitty-gritty of the science, it all comes down to the fact that the repair and recovery of skeletal-muscle tissue is dependent on the “transcription†of certain components of your RNA. And a bout of endurance exercise, combined with low muscle-carbohydrate stores, can result in greater activation of this transcription. In other words, by training in a low-carbohydrate state, you train your body to recover faster.


So, sorry, Wheaties, but it’s true: You don’t have to be a carboholic to be a good athlete.


Despite the sports-gel-chamber-enhanced water bottles on those fancy new bikes, and the tray for your sports gels on the gym’s treadmill, as long as your workout is not performed in a carbohydrate-depleted state, and does not exceed about two hours, there is zero evidence that not consuming carbohydrates during the session will reduce performance. In fact, there is evidence to the contrary—that there is no loss of performance!


Whether these benefits are due to decreased carbohydrate utilization or increased fat utilization is unclear, but there are obvious benefits to going low-carb before and during training. And if it isn’t going to hurt your performance, but it’s going to increase your quality of life, why not eat fewer carbohydrates?


So let’s sum things up:

If you moderately restrict carbohydrates before, during, and after training you may:



  1. Increase activity of the biological mechanisms responsible for building and repairing lean-muscle tissue.
  2. Increase your ability to preserve and ration valuable carbohydrate stores.
  3. Increase your fat utilization during exercise.
  4. Increase the activity of the enzymes responsible for metabolizing carbohydrates during high-intensity exercise, such as racing.
  5. Increase your ability to recover fast.
  6. Increase your health and longevity.

In just a moment, we’re going to dig into some of the common objections you may get from your pasta-pushing, Gatorade-guzzling friends when they find out you’re eating fewer carbohydrates. But, first, please allow me to emphasize that I am not endorsing a zero-carbohydrate diet. I am not even encouraging the popular “fewer than fifty-grams-a-day†carbohydrate diet.


In most cases, when I say low-carbohydrate diet, I’m referring to about 100 to 200 grams a day, and I’ll explain in a moment why. There is one special exception to this rule, called ketosis, which we’ll get into in the next chapter, but most active people (and especially women) do not need to charge into the kitchen with a Sharpie and draw a skull and crossbones on their potatoes unless they want to invite some serious metabolic and hormonal damage.


In other words, just because fewer carbohydrates is good, that does not mean that trace amounts to none is even better. Read the excellent blog post, “Carbohydrates for Fertility and Health,†by my friend Stefani Ruper at paleoforwomen.com if you want more details on this.


Answering Objections

questionsOnce your training partners, family, or other friends learn that you’re eating fewer carbohydrates—or once you begin skipping the obligatory pre-event pasta party—you’re guaranteed to hear criticism and see raised eyebrows. Typically, the objections to a low-carbohydrate diet come in the form of three questions.


Objection 1: Aren’t glucose and carbohydrate necessary for energy during exercise?

As mentioned earlier in this chapter, directly burning blood glucose for fuel causes a significant amount of free radical damage compared with burning storage carbohydrate, storage fats, or circulating fats in the bloodstream. This type of fuel utilization occurs in the athlete trained to eat a gel every twenty minutes during every single training session, or to always have a sports drink on the edge of the pool and a bowl of pasta waiting at home to refuel after a workout.


While cells can certainly burn glucose for energy, fat is a preferred energy source by nearly every cell, and especially by mitochondria, which are the energy-creating organelles within most cells. Until extremely high exercise intensities are reached (rarely the case with endurance athletes) or until you have exercised continuously for two to three hours, fat is a completely usable energy source. Specifically, natural saturated fats, omega-3 fatty acids, and medium-chain triglycerides are extremely dense energy sources whose metabolization produces very few damaging by-products.


The specific parts of the body that do need glucose on daily basis are the brain, the nerves, special proteins called “glycoproteins†(which form compounds like mucus), and cells within the immune system, the gastrointestinal tract, and the kidneys. But the total daily amount of glucose calories required by these body parts is about 500–700 carbohydrate calories, not the 1,500–2,000 consumed by most athletes.


Objection 2: Doesn’t fat lead to cholesterol-related heart disease as well as weight gain?

No! Not only does a high-fat, low-carbohydrate diet produce more weight loss than a low-fat, high-carbohydrate diet, but there is no evidence that the cholesterol particles derived from fat increase risk of heart disease—unless fat consumption is paired with a moderate to high intake of starchy, sugary carbohydrate sources. It is at that point that cholesterol can become oxidized and increase risk of heart disease.


The entire idea that high cholesterol causes heart disease is flawed, and there are entire books that prove it. A very good place to start learning more about the positive and healthy properties of fats would be the website Cholesterol-and-Health.com.


Objection 3: Don’t you need to carbo-load before a race?

We’ll dig into this a little more in the chapter on racing, but once you begin eating a low-carbohydrate diet, your body will, within about ten to fourteen days, begin to become more efficient at burning fat. Although it takes one to two years to adapt to a low-carbohydrate diet to the extent that you will be a fat-burning machine and can ride a bike for hours without eating anything (listen to my “How to Live Like a Polar Bear and Eat Like a Great White Shark†podcast episode with Jack Kruse to learn why at tinyurl.com/bgfjkruse), your basic fat adaptations come more quickly than that. This means that you need relatively fewer carbohydrates during race week or the day before a race, since your body develops an enhanced ability to conserve storage carbohydrate and also an increased ability to utilize fat as a fuel, both during rest and on race day.


What this means is that an entire week of carbo-loading and high sugar intake—which, if your goal is weight loss, health, or longevity, may actually end up doing more harm than good—will not be necessary. Since I have shifted to a lower-carbohydrate intake, I have found that the 85–90 percent carbohydrate diet I once ate during race week actually leaves me sick to my stomach and full of blood-sugar roller-coaster rides all week long.


The only adjustments in nutrition you need to make during race week are:


  1. A slightly more carbohydrate-dense breakfast the day before and the morning of the race;
  2. Moderate amounts of healthy starches with dinner, such as a sweet potato or white rice;
  3. Carbohydrates during the actual race. This would still be considered carbo-loading, but only relatively speaking, not in the traditional sense of seven to ten days of high carbohydrate intake before an event.

More Low-Carb Resources

Just in case that’s not enough ammo to enable you to fire back knowledgeably at your critics, and before I give you some actual carbohydrate, protein, and fat ratios, I have a ton more articles I wrote that I want to share with you. Knock yourself out!



[End of Preview]



This Trevor speaking. Wow, there is so much to learn about fitness and nutrition. The remainder of the chapter Ben lists more low-carb resources and the ideal ratio of carbohydrate, protein, and fat for the average human machine.


My thanks to Ben for supplying our readers with this preview chapter. I look forward to reading the book.


I invite your comments below.