CrossFit South Rockland

Wednesday, April 18, 2012

Paleo, Paleo, Paleo...


I love dining out at restaurants with friends, but nowadays, things can get a little awkward when my wife and I place our orders. Our dining companions' eyebrows inevitably shoot up when we ask for our food sans bread, pasta, rice, polenta or beans. The questions are always the same. “Are you on Atkins or something?” “Trying to lose weight?” “You don't even eat whole grains?” “What the hell is the matter with you?”

Well, here exactly is the matter with me: I EAT PALEO. You know -- kind of like a caveman.

I'm sure this sounds bizarre to folks who aren’t on the Paleo bandwagon (or haven’t even heard of it). Still, the last thing I want to do is to lecture my friends about nutritional science and evolutionary history while we're all trying to eat. (I’ll do it if pressed, but it’s kind of gross when I talk with my mouth full.)

So to avoid proselytizing over the dinner table, I'm offering up this explanation of the Paleo diet -- and why I'm on it -- in (what I hope is) an easy-to-read Q&A format. But caveat lector: There’s a lot to cover, and over 200 linked resources to click through (if you so choose). Take bathroom breaks as needed.

Ready? Let’s go.

To make this “Paleo Primer” more navigable, I’ve split it into seven parts. You can jump around by clicking the links below, but I recommend reading these sections in order (it’ll make a helluva lot more sense!):

Part 1: What is the Paleo Diet?
Part 2: What's Wrong with How We Eat?
Part 3: You Aren’t What You Eat (So Eat Some Fat)
Part 4: Why I Eat Paleo 
Part 5: Mythbusting 
Part 6: Foods to Avoid & Why 
Part 7: Transitioning to Paleo 


Let's start with the basics:

Q: What foods can you eat on a Paleo diet? And what can’t you eat?

A: I do my best to stick to whole, unprocessed foods: meat, eggs, seafood, non-starchy vegetables -- and some (but not a ton of) fruit, nuts and seeds. I try to avoid eating things with sugar, grains (yes, whole grains, too), legumes (and not just because of their fart-inducing properties), and polyunsaturated fats. In short, I eat anything that can be hunted or gathered, and try to avoid stuff that’s processed, cultivated, or sealed in colorful packaging labeled "HEART-HEALTHY!" or "LOW-FAT!" (Really. I’ll explain later.)

My favorite description of the Paleo approach can be found on the Whole9 site:
I eat “real” food -- fresh, natural food like meat, vegetables and fruit. I choose foods that are nutrient dense, with lots of naturally-occurring vitamins and minerals, over foods that have more calories but less nutrition. And food quality is important -- I’m careful about where my meat comes from, and buy produce locally and organically as often as possible.
It’s not a low calorie “diet” -- I eat as much as I need to maintain strength, energy and a healthy weight. In fact, my diet is probably much higher in fat than you’d imagine. Fat isn’t the enemy -- it’s a great energy source when it comes from high quality foods like avocado, coconut and nuts. And I’m not trying to do a “low carb” thing, but since I’m eating vegetables and fruits instead of bread, cereal and pasta, it just happens to work out that way.
Eating like this is good for maintaining a healthy metabolism, and reducing inflammation within the body. It’s been doing great things for my energy levels, body composition and performance in the gym. It also helps to minimize my risk for a whole host of lifestyle diseases and conditions, like diabetes, heart attack and stroke.
Sound good? Want to give it a try? If so, a great place to start is Robb Wolf's Quickstart Guide. Check out his book, "The Paleo Solution," too -- it's one of the best and most accessible Paleo primers out there. Hisweekly podcasts are a big hit in our household, too. And watch his video on Paleo fundamentals:

Other excellent sources of Paleo information for beginners: 

If you’re a visual learner, check out this handy infographic.

If you're feeling bookish, Loren Cordain's "The Paleo Diet" and Mark Sisson's "The Primal Blueprint" introduced the concept of ancestral eating approaches to tons of people, and more recently, Art De Vany (another pioneer of this movement) wrote "The New Evolution Diet."

If you'd rather gaze into a computer screen, you may want to start with Cordain's Paleo Diet FAQ, Sisson's how-to on living "Primally," and De Vany's website, Evolutionary Fitness.

Want more? Read "Eat Like a Predator, Not Like Prey." This page on Melissa McEwen's site also contains lots of useful resources for newbies. Hivelogic's Paleo link primer is a great starting point, too. (And I'm not just saying that 'cause my wife's blog is listed as a Paleo cooking resource.)

While you're at it, check out this list of resources on the Whole9 site, as well as Diane Sanfilippo's Practical Paleo Nutrition Guidebook.

Q: Whoa! Not so fast. This sounds weird. No bread, cereal or pasta? Give me one good reason why you're doing this to yourself.

A: Here are ten.

What? Not good enough?

I hear you. Frankly, I resisted going Paleo for a quite a while. But after digging into the science, I'm now convinced that from the perspective of evolutionary biology, humans are poorly adapted to eating the majority of modern (or “Neolithic”) foods like grains, sugar, processed vegetable and seed oils, and other bad stuff. A strong case can be made that the “diseases of civilization” -- including metabolic syndrome, cardiovascular disease, diabetes, obesity, etc. -- are due to the consumption of foods that only became widely available ten to fifteen thousand years ago, with the rise of agriculture.

John Durant summarized the premise of Paleo eating brilliantly:
Nearly all conventional health authorities recommend that you move from an Industrial Diet (processed foods, soda, Pop Tarts) to a traditional Farmer's Diet (whole grains, dairy, organic). It's a good first step. I'm simply recommending that we go one step further back in time, to a Hunter-Gatherer Diet.
And that's it! Really, that's it. It needs to be no more complicated than that. Remove processed foods. Remove farmer foods. DONE.
For me, it really boils down to this: Eating Paleo has made me quantifiably healthier, leaner, and stronger. My body composition has improved, and I feel better, too.

Q: So does this mean you're eating like those weirdo hipster "cavemen" who were profiled in the New York Times a while back?

A: Yeah, pretty much. A more detailed description of how I eat can be found here or here.

I want to point out, though, that while the “Paleo” approach is fairly consistent with the way I choose to eat, I’m not at all obsessive about eating only the stuff that was available to actual cavemen. (More on this in a bit.)

Q: What's the difference between the Paleo diet and Atkins? And how do you distinguish between "Paleo" and "Primal"?

A: Check out this handy infographic by Melissa McEwen (who, along with John Durant, are two of the aforementioned "weirdo hipster cavemen"). But the quick answer is that Atkins is less concerned about food quality than it is about weight loss via restricting carbohydrate intake. (As we’ll discuss in a bit, most Paleo eaters end up consuming fewer carbohydrates than most people simply because we avoid grains and processed foods -- but unlike Atkins, carbohydrate avoidance ain’t necessarily the name of the game.) And super-strict orthodox "Paleo" eating tends to be more strict than Mark Sisson's "Primal" approach, which makes allowances for certain additional foods, like dairy and "natural" sweeteners.

(And frankly, there are even schisms within the "Paleo community." We'll discuss that, too.)

Q: Back up. Paleo eaters avoid dairy? Do you? If so, why?

A: Dairy can present a host of health problems -- and not just for those who are lactose intolerant. Super-strict, by-the-book Paleo eaters don’t touch the stuff.

(For a good explanation of the case against dairy, check out Pedro Bastos' presentation from the 2011 Ancestral Health Symposium.)

But some dairy products seem to present less of a problem due to their source (A2 dairy, grassfed butter), fermentation (yogurt, kefir, cheese), or the elimination of milk solids (ghee). To paraphrase Kurt Harris, just 'cause dairy's Neolithic or technically un-Paleo doesn't mean that every dairy product is an agent of disease.

I could write in more detail about the dairy issue (and I have – overhere), but to cut to the chase, I’m generally okay with eating the “more-okay-than-not” full-fat dairy products listed above. Don't get me wrong: We're not guzzling the stuff -- but we do enjoy a bit of raw Jersey (A2!) cream in our coffee, and we're not going to send a salad back if there's a little cheese on it. If you want to call me a half-assed Paleo eater, go right ahead. Again, I’m not hung up on the label. 

If -- after cutting dairy out of your diet and reintroducing it after a month -- you find that you can tolerate it just fine, go for it. (Just go in eyes wide open.)

Q: So if you're eating some dairy, you're not really on the Paleo diet, right?

A: This is important: THERE IS NO ONE DEFINITIVE "PALEO DIET." Even cavepeople ate different diets. And as I discuss below, the point isn't to mimic the precise eating habits of our prehistoric ancestors. Rather, the point is to stick with food choices for optimal health in a modern world. Here's what Chris Kresser has to say about this topic:
[W]hat is a Paleo diet? Is it low-carb? Low-fat? Does it include dairy? Grains?

The answer to that question depends on several factors. First, are we asking what our Paleolithic ancestors ate, or are we asking what an optimal diet for modern humans is? While hard-core Paleo adherents will argue that there’s no difference, others (including me) would suggest that the absence of a food during the Paleolithic era does not necessarily mean that it’s not nutritious or beneficial. Dairy products are a good example.

Second, as recent studies have revealed, we can’t really know what our ancestors ate with 100% certainty, and there is undoubtedly a huge variation amongst different populations. For example, we have the traditional Inuit and the Masai who ate a diet high in fat (60-70% of calories for the Masai and up to 90% of calories for the Inuit), but we also have traditional peoples like the Okinawans and Kitavans that obtained a majority (60-70% or more) of their calories from carbohydrate. So it’s impossible to say that the diet of our ancestors was either “low-carb” or “low-fat”, without specifying which ancestors we’re talking about.

Third, if we are indeed asking what the optimal diet is for modern humans (rather than simply speculating about what our Paleolithic ancestors ate), there’s no way to answer that question definitively. Why? Because just as there is tremendous variation amongst populations with diet, there is also tremendous individual variation. Some people clearly do better with no dairy products. Yet others seem to thrive on them. Some feel better with a low-carb approach, while others feel better eating more carbohydrate. Some seem to require a higher protein intake (up to 20-25% of calories), but others do well when they eat a smaller amount (10-15%).
I agree wholeheartedly that we ought to be following a "Paleo template" rather than a "Paleo diet." After all, "following a diet doesn’t encourage the participant to think, experiment or consider his or her specific circumstances, while following a template does." A template allows for flexibility, while still generally following certain dietary guidelines. Here are Chris' rules of the road:
  • Don’t eat toxins: avoid industrial seed oils, improperly prepared cereal grains and legumes and excess sugar (especially fructose) 
  • Nourish your body: emphasize saturated and monounsaturated fat while reducing intake of polyunsaturated fat, favor glucose/starch over fructose, and favor ruminant animal protein and seafood over poultry 
  • Eat real food: eat grass-fed, organic meat and wild fish, and local, organic produce when possible. Avoid processed, refined and packaged food.
Within these guidelines, however, there’s a lot of room for individual differences. When people ask me whether dairy products are healthy, I always say “it depends”. I give the same answer when I’m asked about nightshades, caffeine, alcohol and carbohydrate intake.

Q: So how long are people supposed to stay on this "diet""template"?

A: Another important point: THE PALEO APPROACH IS NOT A WEIGHT-LOSS DIET. (This is another reason why I'm not a huge fan of calling this nutritional approach the "Paleo Diet"; it's confusing to people.) Here, the word "diet" is intended to mean "food choices" or "nutritional approach" -- not to mean "shed 30 pounds in 30 days!"

Besides, unlike some folks who flirt with a low-carb or Atkins diet, it's not like I have a lot of weight to lose -- and once I hit my target weight, I'll go back to eating "normally." The idea is that this lifestyle change is permanent -- or at least until I'm persuaded that another approach is superior. It's going to take a lot of convincing, though.

Q: Come on. This "caveman" thing is ridiculous. What are you going to do next -- strap on a loincloth and finger-paint pictures of buffaloes in a cave by torchlight? Club a hirsute woman and drag her around by her hair?

A: Uh, no. Believe it or not, I'm using a space-age tool called a “laptop computer” to generate this post.

I use the term “Paleo” as an easy shorthand for how I eat, but I’m not trying to live like a caveman, and I certainly don’t romanticize prehistoric life.

Again: The reason I eat this way is to optimize my health -- not so I can slavishly replicate a caveman's actual diet. Ancestral diets point us in the direction of better nutrition. They explain why we're not evolutionarily equipped to thrive on certain types of "modern" foods. It gives us clues as to why the Standard American Diet's emphasis on massive loads of industrially-processed, chemically-engineered supermarket staples over real food is a very bad thing. But it shouldn't dictate every last morsel we stick into our mouths. Many of the foods I eat today weren't available to my prehistoric ancestors (unless they were regularly chowing on avocados, bacon, mac nuts and coconut flakes), but as long as they're not detracting from my health -- and I continue to look, feel and perform to my satisfaction -- who cares?

I subscribe to Mat Lalonde's pragmatic approach to nutrition. His point of view is that our backward-looking observations about ancestral eating patterns are useful only as a rough guidepost on the road to optimal nutrition. From these observations (e.g., "Hey! Pre-agricultural societies that don’t eat grains / legumes / dairy don’t appear to suffer from diseases of civilization!"), we can build hypotheses (e.g., "Maybe we're not meant to eat grains and legumes! Maybe animal fat and meat ought to play a larger role in our diets!"). But these theories still need to put to rigorous scientific testing and validation.

Therefore, if peeled potatoes don’t negatively impact my health (and I'm not trying to lose flab by using a low-carb approach), I'm not going to cut ‘em out of my diet entirely just because spuds weren’t available to Paleolithic Man. I don’t restrict myself to eating only those foods that pre-date agriculture for the sake of precisely re-creating a museum-quality Paleolithic tableau. You won’t find me huddling in a cave, rubbing two sticks together.

As noted by astute online commenter John Ryan, "Paleo is a logical framework applied to modern humans -- not a historical reenactment." Besides, I think indoor plumbing is super-awesome.

So if the "Paleo" name gets you riled up, or you think that "caveman diet" sounds stupid, feel free to call it something else. It's just that "Anti-Immunogenic/Low Anti-Nutrient Diet" doesn't roll off the tongue quite as easily, and "Perfect Health Diet" might come across as too presumptuous and aspirational.


Q: Hold on a second. If you’re cutting out all grains, legumes, sugar and dairy, you’re basically eating fewer carbs and replacing it with fat, right? Doesn't eating fat make you fat -- not to mention dangerously prone to cardiovascular disease?

A: Time to unleash some boring science! To understand how all this stuff works, we need to reassess basic theories of weight loss.

The Caloric Balance Theory

First, some fundamentals.

All food is comprised of three primary macronutrients -- fat, protein and carbohydrates -- that power our bodies with energy in the form of calories. The First Law of Thermodynamics, also known as the principle of energy conservation, says that energy can be transformed, but can't be created or destroyed. You know: Energy in, energy out. In the context of diet, then, the caloric energy in the food we eat can’t just disappear. It has to be stored (as fat) or used (to power, maintain and grow the human body). Calories in, calories out.

Out of this was born the old familiar “Caloric Balance Theory” (a tip of the hat to Adam Kosloff) which maintains that if you ingest more calories than you burn, your body’ll end up storing the remaining calories. In other words, excess calories make us fat. If we eat too much and move too little, we’ll throw our caloric balance out of whack and start putting on some pounds. On the other hand, if we simply eat less and move more, we’ll burn off our existing fat stores and lose weight.

This is the message we've been spoon-fed for decades. And it’s true that if you consistently or drastically overfeed, you’ll get heavier. But that’s not the whole story.

You Aren’t What You Eat

It’s well established that dietary fat -- the fat you eat -- is more calorically dense than protein or carbohydrates. In fact, each gram of fat consumed provides more than twice as many calories as a gram of protein or carbohydrate. Applying the Caloric Balance Theory, people looking to shed body fat have naturally glommed onto the idea that we should avoid eating dietary fat, and choose less calorically dense foods instead.

Plus, for decades, we’ve all heard that excessive fat intake correlates with a host of health problems, from cardiovascular disease to diabetes. Since we all know (or think we know) that these diseases are linked to obesity, many of us conclude that dietary fat must therefore cause obesity. Who cares if correlation doesn’t amount to causation? As the saying goes, “you are what you eat” -- so if you eat dietary fat, your body will turn into fat, right?

If the key to weight loss and overall wellness is to take in fewer calories, and if dietary fat makes us fat and sick, the solution, it would seem, is to go low-fat -- right?

Sounds reasonable. And over the past few decades, it’s become the common refrain among the vast majority of doctors, food companies, health authorities and nutrition experts. Dissenters are dismissed as conspiracy theorists, fringe scientists and bacon-obsessed Atkins groupies whose glucose-deprived brains have misfired. As a consequence, the low-fat movement has not only persisted, but has been widely and blindly accepted as fundamentally true -- despite mounting evidence to the contrary.

What Really Causes Obesity?

The short answer: Excess carbohydrates. Especially sugar.

Admittedly, I’m no scientist, and I'm far from articulate on the subject of human metabolism. But my reading comprehension skills are decent, and I've gleaned quite a bunch from Gary TaubesMichael and Mary Dan EadesWeston A. PriceLoren CordainRobb WolfKurt Harris and others:
  • When eaten, neither protein nor fat -- without carbohydrates -- has any effect on blood glucose. But when we take in carbohydrates, our blood sugar levels shoot up. (This isn’t news; in fact, it’s the scientific basis underpinning the popular movement away from eating refined carbs like white bread, which have the effect of suddenly spiking blood glucose. But as we’ll discuss later, whole grains aren’t the bees’ knees, either.)
  • Whenever blood glucose levels rise, the pancreas reacts by releasing a surge of insulin into the bloodstream. Insulin is a hormone that happens to be the primary mover and shaker in human metabolism. Among its many functions, insulin manages nutrient storage by driving excess blood sugar, fats and protein into the interior of our cells, where they can be used as energy or stored as fat.
  • Although there are numerous factors that can affect how much insulin we produce, as well as how our bodies respond to insulin and blood sugar, the basic rule is this: The more carbohydrates we eat, the more insulin we end up secreting in reaction to the spike in blood sugar.
  • As a result, two key things happen:
    • First, with all the excess blood sugar and surge in insulin, the liver no longer stores glucose as glycogen -- a fuel source for the body. Instead, the glucose is synthesized into fatty acids, which are exported from the liver as lipoproteins. These lipoproteins are ripped apart as they circulate through the body, providing free fatty acids to be sucked up into the body’s cells -- including the body’s adipose fat cells, in which the fatty acids are then “bound up” together to form triglycerides.
    • Insulin also inhibits the breakdown of fat in adipose tissue by interfering with the mechanisms that enable triglycerides to split into their constituent fatty acids. Triglycerides are bigger than fatty acids -- and too big to escape our adipose fat cells. In other words, once triglycerides form in your adipose fat cells, the excess insulin produced by your body makes it difficult for you to break them back down. So when we eat more carbohydrates and produce more insulin, more triglycerides -- which are also now prevented from breaking down into fatty acids -- are synthesized and locked up inside our fat cells.
  • And so, over time, our fat tissue swells.
In summary, if you take in carbohydrates in excess, your adipose fat tissue’s likely to expand. You get fat.

If my technobabble doesn’t make make sense, take a look at this video:

But wait – there’s more! An excess of insulin in our blood isn’t just bad because gives you an unsightly muffin-top. It’s bad because it can make you very, very sick.

Let’s say you’re a carb junkie. You stock up on bread, pasta, rice and 100-calorie packs of Snackwells because they’re low-fat. They know you by name at Jamba Juice and Auntie Anne’s Pretzels. The constant bombardment of sugar in your bloodstream -- and the excess insulin released to move the sugar out of your blood -- eventually blunts your insulin receptors to the effects of the insulin. (Your insulin sensitivity is down-regulated -- kind of like what happens when you linger in a busy kitchen for more than a few minutes: Soon, the cooking smells seem to fade.)

The likely result? Insulin resistance -- a.k.a. pre-diabetes -- meaning your insulin receptors are no longer efficiently activated by the constant rush of insulin that’s secreted to deal with the sugar in your bloodstream. Your insulin receptors lose their ability to effectively move the sugar out of your blood, so when you eat carbs, your blood sugar level stays high -- which, in turn, triggers your pancreas to pump out more and more insulin until there’s finally enough to get your sluggish insulin receptors to do what they’re supposed to do: lower your blood glucose level.

But now, you have a crapload of excess insulin floating around in your system. Bad news. This condition, also known as hyperinsulinemia, leads directly to Metabolic Syndrome (a.k.a., Syndrome X): a cluster of disorders including coronary disease, Type II diabetes, hypertension and obesity. Not fun.

Again, I'm no scientist. I'm just another idiot with a library card and a big mouth, so you have no reason to put any faith in what I've just written above.

But if you're at all interested in the science of fat metabolism, I urge you to read "Good Calories, Bad Calories," which lays out a much more compelling case than I ever could. For those who can’t stand the thought of sifting through the science-y stuff, Taubes recently penned an easier-to-read volume entitled “Why We Get Fat: And What To Do About It.” And for those of you who can’t be bothered to read a book of any length at all, skim these notes or read this summary of "Good Calories, Bad Calories."

(Although I'm kind of bashing carbs here, note that Paleo eating isn't necessarily low-carb. But because grains, legumes and sugar are verboten, Paleo enthusiasts tend to take in fewer carbohydrates than most people. Another way of thinking about this: The Paleo crowd isn’t “low-carb”; it’s everyone eating the Standard American Diet who are eating high-carb.)

Q: But isn’t weight control all about willpower and following the "calories in, calories out" rule?

A: Not exactly. Calories aren't all created equal.

Take another look at the First Law of Thermodynamics. The Caloric Balance Theory suggests that an imbalance between caloric intake and energy expenditure drives changes in weight. But that’s not necessarily the case. Under the First Law of Thermodynamics, it’s equally possible that the reverse of the equation is true: a change in weight causes caloric imbalance.

As Taubes puts it:
[S]ome regulatory phenomenon could drive us to gain weight, which would in turn cause a positive [or negative] energy balance -- and thus overeating and/or sedentary behavior. Either way, the calories in will equal the calories out, as they must, but what is cause in one case is effect in the other... This simple misconception has led to a century of misguided obesity research.
But under Taubes’ theory, what type of “regulatory phenomenon” is driving the development of beer bellies, saddlebags and big asses?

Taubes’ answer: The lipophilic -- a.k.a., fat-loving -- properties of our bodies’ adipose fat tissue. Simply put, by eating massive amounts of carbs, we seriously screw up our insulin levels, and therefore, our metabolism. Excess insulin causes our adipose tissue to swell, and we get fat. And -- consistent with the First Law of Themodynamics -- this change in weight causes a caloric imbalance, which triggers hunger. So we eat more. (To learn more about this “lipophilia theory” without having to go to the bookstore, check this out.)

Don’t get me wrong: I’m not saying that the First Law of Thermodynamics works only in this one direction, and that it’s always a change in body weight that drives a change in caloric consumption. I’m suggesting that the First Law of Thermodynamics is a two-way street; while changing our caloric intake can certainly affect our weight, changing our weight can also affect our caloric intake.

Q: So calories still count?

A: Yes. Kind of.

Face it: If you go hog-wild and ingest tons of excess calories a day, you're bound to gain weight. And on the other end of the spectrum, caloric restriction will spur weight loss. Even if you're subsisting on Twinkies.

But when it comes to weight management, strict calorie-counting is kind of pointless because your body’s metabolism (assuming it’s not been thrown out-of-whack) has a way of maintaining its natural set-point. Homeostasis is a wonderful thing.

All calories are not created equal. Given what we know about the insulin-driving properties of dietary carbohydrates, sucking down a Neverending Pasta Bowl at the Olive Garden is likely to make you fatter than having a steak -- even if you're taking in the same number of calories. Weight loss just isn't as simplistic or one-sided as advocates of the Caloric Balance Theory would have you believe.

If you take two people of the same weight -- one on a high-carb diet and one on a low-carb diet, but both eating the same number of calories -- both will shed pounds if there’s a caloric deficit. That’s just the nature of the First Law of Thermodynamics.

But the carb fiend is going to be releasing more insulin than the low-carb eater, and that excess insulin’s going to interfere with the breakdown of triglycerides in fat cells. Recall that not only does insulin store fat in adipose fat cells, it also prevents the fat that is already in a fat cell from breaking up into fatty acids and exiting the cell. So all else being equal, the high-carb eater’s going to hold on to more fat than the low-carb eater.

Also, not to get too science-geeky or anything, but we should touch briefly on lectins and leptins. There's evidence that foods high in lectins (like cereal grains and legumes) trigger leptin resistance. Leptins are hormones that tell you when you're full, so when you're leptin resistant, you tend to keep on eating. Conclusion: When you eat a crapload of carbs, the result is that you have a much more difficult time reaching satiety, and you end up eating even more.

Q: You're telling me that eating carbs make you want to eat more?

A: Yes. Specifically, carbs make you want to eat more carbs.
In addition to what I described above, you should know that grains are addictive. Here’s a paragraph from “The Origins of Agriculture – A Biological Perspective and a New Hypothesis” by Greg Wadley and Angus Martin:
The ingestion of cereals and milk, in normal modern dietary amounts by normal humans, activates reward centers in the brain. Foods that were common in the diet before agriculture (fruits and so on) do not have this pharmacological property. The effects of exorphins are qualitatively the same as those produced by other opioid and/or dopaminergic drugs, that is, reward, motivation, reduction of anxiety, a sense of well being, and perhaps even addiction. Though the effects of a typical meal are quantitatively less than those of doses of those drugs, most modern humans experience them several times a day, every day of their adult lives.
Now you know why folks are addicted to cookies and cupcakes, but not eggs and ribs. Take away their carbs, and the junkies go into withdrawal.

But wait -- there's more! Serious dieters tend to exercise. A lot.Exercise -- especially chronic cardio -- makes people want to eat moreReally. And exercise makes 'em hungry for carbs in particular. Plus, low-fat dieters are apt to ditch fat and protein in favor of more carbs because they’ve been told that this is better and healthier for them. But as I've pointed out , eating carbs actually makes folks want to eat even more -- and specifically, more carbs. What comes next? Caloric excess. Plus, the carbs they eat will drive fat into their fat cells, where they’ll stay trapped.

Let's face it: We all know people who constantly diet and exercise like crazy, but never seem to lose much weight. (Don't tell me you've never seen a less-than-svelte aerobics instructor or a plus-sized jogger with ham-hock shoulders and thighs.) Could it be because they’re starving from all the incessant cardio they're doing, and then snarfing up carbs because they mistakenly think they've "earned" an extra cupcake?

Even if they restrict themselves low-fat and fat-free foods, a lot of folks can't seem to shed the pounds. Is it because they're eating lots of pasta and bread, thinking that these "low-fat" foods will somehow prompt weight loss?

I think we can all agree that starvation diets -- the kinds featured on TV shows like "The Biggest Loser" and "Oprah" -- are not sustainable. A body can't run at a calorie deficit forever. Is it any wonder calorie-restriction diets are also known as yo-yo diets?

Q: So if you’re so anti-carbs, why don’t you just follow the Atkins Diet?

A: First of all, I’m not anti-carbs as a blanket matter. Demonizing carbs doesn’t make a lot of sense -- especially given that people like the Kitavans of Papua New Guinea are healthy and thriving despite subsisting on a high-carb diet. The role of excess carbohydrate intake in the development of insulin resistance, obesity and metabolic diseases is just one piece of the puzzle. We also have to consider the role of pro-inflammatory agents in certain foods, the leptin content in grains and legumes (discussed above), and each individual person’s need for glycogen repletion (for example, after strenuous activity).

While many Paleo eaters skew towards the low-carb side (especially those who are still in the process of losing body fat and reversing their metabolic problems), there are plenty of others -- myself included – who actually eat a good amount of carbs on a regular basis. I consume lots of vegetables and a moderate amount of fruit. Plus, after every workout, I wolf down a big ass sweet potato with some protein. I’m clearly not going out of my way to go low-carb. But by avoiding processed foods (which are chock-full of sugar, grains and/or legumes), I’m still consuming far less in the way of carbohydrates than most people.


Q: This "Paleo" business sounds like snake oil. It’s totally antithetical everything that the experts have taught us about the importance of low-fat diets. Everyone knows that “you are what you eat.” Low-fat equals heart-healthy, and high-fat equals clogged arteries and early death.

A: I know this contradicts everything that we’ve been taught. It took me a while to get on board, too. But bear with me for a little longer while I try to convince you that it's the low-fat approach that's full of crap.

We all know that conventional wisdom says to eat a low-fat diet. The USDA Food Pyramid was built on the hypothesis that dietary fat is bad for you, and the newly-unveiled “MyPlate” isn’t much better. To avoid dietary fat and still eat enough calories to fuel your body, you’d have to increase your intake of protein and/or carbohydrates. But here’s the thing: Most foods are made up of a combination of macronutrients. If you try to eliminate fatty foods, the easiest items to eliminate are ones that are also chock-full of protein, such as meat, eggs and nuts. By eliminating fat, you also end up drastically reducing your intake of protein. And in their place, you substitute lots and lots of carbs. After all, there are plenty of low-fat, high-carb foods.

This works out great for industrial agribusiness, which is almost single-mindedly focused on the (over)production of dirt-cheap, government-subsidized staples like corn, wheat and soybeans. These carby crops are in everything -- from ketchup and soda to salad dressing and unnaturally grain-fed cattle. And it’s making us fat. Professor James Tillotson of Tufts University has argued that:
U.S public policy encourages obesity at the expense of sound nutritional practices. “You have a whole rĂ©gime here that’s worked to increase agricultural efficiency,” Tillotson says. And what U.S. farmers are most efficient at producing, he says, are just a few highly subsidized crops -- wheat, soybeans, and especially corn.
I'm not going to belabor the point, but for more on this subject, watch "Food Inc." or this PBS documentary that summarizes the documentary's most salient points. And while you're at it, check out "King Corn," too.

You can also watch the entire feature-length documentary “Fathead” for free right here, courtesy of Hulu.

Q: But we hear all the time about low-fat, low-calorie foods and how they're fantastic for our health!

A: But who's delivering the message? You may think I'm a nutjob conspiracy theorist, but ask yourselves the following questions:
  • Why do you believe that low-fat diets are healthy?
  • Is it because you’ve read the studies and agree with the findings? Or are you just accepting as gospel truth the media’s sloppy reporting of the findings?
  • Do you put your faith in low-fat diets because eating low-fat stuff has worked miracles for you, enabling you to lose weight and keep it off without starving?
  • Or is it because food marketers and/or so-called experts who receive funding from agribusiness have drilled it into your head, and everyone around you has been parroting and reinforcing the low-fat language?
Let’s just take one example. Not too long ago, Fitness Magazine unveiled its list of the 55 "healthiest" foods available at grocery stores. Here's just a sampling of the foods Fitness claims are the "Best Snacks" (the best and most healthy!) available in your supermarket:
  • Michael Season's Baked Cheddar Cheese Curls
  • Cape Cod 40% Reduced Fat Potato Chips
  • Dove Silky Smooth Milk Chocolate Peanut Butter Singles Bar
  • Pepperidge Farm Gingerman Homestyle Cookies
  • Late July Organic Dark Chocolate Sandwich Cookies
  • Nestle Cherry Raisinets
  • York Pieces Candies
Unsurprisingly, the magazine touts the fact that these super-processed, chemically-altered items are "low-fat" and "low-calorie," but says nothing about the carb or sugar count in these concoctions. But in case you're curious, Nestle Cherry Raisinets contain 32 grams of carbs per serving (28 grams of sugar!) and York Pieces Candies contain 28 grams of carbs per serving (23 grams of sugar!). Compare those numbers with the nutrition information for a serving of M&Ms -- candies that no one's ever mistaken for a health food: 15 grams of carbs and 13 grams of sugar. (Methinks M&M candies should protest their exclusion from Fitness Magazine's list of "healthiest" snack foods.)

Or better yet, compare Fitness Magazine's list of "Best Snacks" against Mark Sisson's list of Primal Blueprint-approved snacks, which include:
  • Seeds and nuts
  • Hardboiled eggs
  • Smoked salmon
  • Avocado/guacamole
  • Fresh and dried fruit
  • Veggies
  • Jerky
  • Dark Chocolate
Which list strikes you as being truly healthier? And which list do you think was the product of marketers working to promote the soy/corn/wheat products of the industrial food complex?

Hint: It's the one that describes these sugary delights as one of the 16 healthiest things you can buy at the grocery store:

I'm going to go out on a limb and say that most of the nutrition articles in fitness magazines aren’t worth the paper they’re printed on.

Q: Crapping on a glossy magazine is easy, but what does science actually have to say about the low-fat hypothesis?

You can’t talk about the “science” behind the low-fat approach without introducing Ancel Keys.
Believe it or not, the low-fat hypothesis didn’t emerge until the middle of the 20th century, when Keys, a prominent University of Minnesota professor, began shouting it from the mountaintops. Before Keys emerged on the scene, the scientific community pretty much agreed that insulin -- not dietary fat -- is the primary driver of fat metabolism.

But Keys’ new theory was compelling in its simplicity. His basic claim was that "you are what you eat": If you eat dietary fat -- in particular, saturated fat -- and dietary cholesterol, your body will turn into fat and you’ll develop higher levels of blood cholesterol. He also theorized that elevated blood cholesterol leads to heart disease. As evidence, he pointed to his “Seven Countries Study,” a landmark observational study of the eating habits of seven countries that seemed to validate the correlation between dietary fat and cholesterol and heart disease.

But Keys’ study was fatally flawed. It turns out that Keys had access to data about not just seven countries, but many, many more. (Twenty-two, to be exact.) He cherry-picked the seven countries with the data that supported his theory -- and ignored the data from countries that didn’t support his low-fat hypothesis. In fact, an examination of all the countries shows no evidence that low-fat or low-saturated-fat diets have any health benefits. Nonetheless, Keys’ theory was publicized and heralded by the national media to the point that it was no longer considered an unproven hypothesis, but a hard, proven fact. Keys even made the cover of Time Magazine.

Succumbing to the effects of confirmation bias, a number of (lazy, sloppy) scientists followed Keys’ lead over the next few decades. And health professionals and food marketers followed, making Keys the poster boy for the low-fat movement. Key's unsupported hypothesis was enshrined as unassailable truth -- and contradictory evidence was simply dismissed. (Read more about Keys here.)

For example, in the early 1960s, researchers from Vanderbilt University Medical School found that the Masai tribal people of Kenya -- who ate a high-saturated-fat carnivorous diet of meat and milk -- had exceedingly low blood cholesterol levels and heart disease rates. But when Keys and his colleagues were confronted with the Masai experience, they simply dismissed the data, claiming that the Masai were somehow genetically different from Westerners.

(The Masai aren’t alone. The Inuit, Tokelauans, Zulus and Gabonese are among numerous modern-day hunter-gatherer groups with negligible rates of heart disease, diabetes and obesity despite eating native diets high in dietary fat and cholesterol. Things changed, however, when they began to adopt a typical Western diet full of sugar and grains.)
Next, the 1968 Minnesota Coronary Survey was conducted in an attempt to confirm Keys’ theory, but the results were not published until the 1980s because they did not support the low-fat hypothesis. Similarly, the data from the well-known Framingham Nurse’s Studyshowed little correlation between blood cholesterol and heart disease risk -- but the exact opposite was publicly reported.
The government wasn't immune to this effect. In 1977, George McGovern adopted Keys’ hypothesis as fact, and relied upon it to develop the “Dietary Goals for the United States,” a document that led to the development of the good ol’ USDA food pyramid and dictated government health policy ever since. In the mid-1980s, the NIH effectively closed the book on the debate over the effects of dietary fat by declaring that there was scientific consensus behind Keys’ theory -- despite the fact that plenty of critics were pointing to evidence contradicting the far-reaching claims about the health benefits of low-fat eating.

For example, as Gary Taubes has written, the Nurses Health Studyconducted in the 1980s concluded that there was a correlation between increased saturated fat intake (and decreased carbohydrate intake) and reduced risk of breast cancer. And yet the American Cancer Society continued to urge restricting red meat intake until 2006, when the lack of correlation between fat consumption and cancer risk was finally acknowledged. Additionally, studies conducted in the 1980s and 90s showed that very low blood cholesterol is associated with increased occurrence of cancer and respiratory diseases, and in women, higher cholesterol is not associated with any increase in mortality risk.

But who needs facts when you can eat fat-free potato chips (anal leakage and all)?
The best evidence that dietary fat and cholesterol aren’t driving heart disease rates? Despite decades of government mandates, mass marketing and drastic reductions in fat and cholesterol intake, there has been no resulting decrease in heart disease rates in America. And in case you haven't noticed we are getting fatter and fatter. Since 2007,the number of states with obesity rates over 30 percent has tripled -- low-fat 100-calorie packs of Snackwells notwithstanding.

Q: So are you saying we should just load up on protein and fat? 

A: Yeah. Mostly fat, actually.

Humans can't survive on protein alone. If you get more than a third or so of your total calories from lean protein, you'll get diarrhea. Do this consistently and you'll die of rabbit starvation.

So ideally, you should be eating lots of fat.

Q: No way! Dietary fat'll clog your arteries! You'll die!

A: Have you been paying attention? Or are you still drinking Ancel Keys' (low-fat) Kool-Aid?

The whole "artery-clogging saturated fat" hypothesis is nothing more than junk science. In January of 2010, researchers published the results of a massive meta-analysis of over a third of a million subjects, and concluded that "there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD." NONE. As Scientific American pointed out, carbohydrate intake is far worse than eating saturated fat.

Plus, emerging evidence indicates that "cardiac dysfunction and HF [heart failure]...may be prevented or slowed by maintaining low body fat and high insulin sensitivity and consuming a diet of low glycaemic load that is high in mono- and polyunsaturated fatty acids."
If you're looking for more on this topic, check out The Heart Scan Blogand Chris Masterjohn's The Daily Lipid.

Q: Fine. But how do we distinguish between "good" and "bad" fats? 

A: As I pointed out above, you first need to throw out everything you've been told about dietary fat. It's all crap. Next, read Mark Sisson's Definitive Guide to Fats. Want to dig deeper? Read Kurt Harris' post on fats. If you have it, review chapter seven of Robb Wolf's "The Paleo Solution," too. And if you're really interested in the details, shell out fifty bucks to watch the six-hour video of Mat Lalonde's Nutrition Seminar online and comb through his hundreds of pages of materials. I can't come anywhere close to explaining the science of fats as well as these folks.

But if you're just looking for a quick-and-dirty guide about what types of fat to eat or avoid, check out Diane Sanfilippo's post on good versus bad fats.

If that's still not enough for you, here are my two cents:

As I mentioned above, eating saturated fat is fine, and are evenbeneficial to human health. Saturated fat can be found in meat and some tropical oils. (But due to the grain-feeding of animals in the U.S., the saturated fat found in their meats is abnormally high in palmitic acid, which can increase LDL cholesterol, so try to stick with grass-fed meat, wild-caught fish and game, coconut oil, etc.)
  • Saturated Fats
I know what you’re thinking. You’re thinking that any kind of fat that’s described as “saturated” must be incredibly damaging and artery-clogging, right? Well, you’re wrong. All it means is that there are no double-bonds between the individual carbon atoms of this particular fatty acid chain. In other words, the chain of carbon atoms is fully "saturated" with hydrogen atoms, making it more chemically stable.The mere fact that it's "saturated" doesn't mean it’s bad.

Saturated fat won't put you at risk of developing cardiovascular disease -- provided that you're limiting your carb intake. As Robb Wolf puts it:
A high intake of saturated fats, in conjunction with a high intake of dietary carbohydrate, is a hell of a combo for an early grave... [E]levated insulin levels lead to a shift in the LDL particles to a type that is small, dense, and easily oxidized. This is bad for a number of reasons, but the central feature is increase systemic inflammation and a subsequent increased probability of a cardiovascular event like heart attack or stroke. No bueno.

So don't think that my advocacy of eating certain saturated fats means you can regularly gorge on both bacon and cupcakes.
  • Monounsaturated Fats (MUFAs)
Eat 'em -- they're good for you. MUFAs help with insulin sensitivity and lower cholesterol, among other things. Good sources of MUFAs include meat, macadamia nuts, avocados and olive oil.
  • Polyunsaturated Fats (PUFAs)
There are two key categories of PUFAs: Omega-6 fatty acids and Omega-3 fatty acids. These PUFAs are essential, meaning that our bodies need 'em but can't make 'em, so you have to eat 'em. The challenge, however, is that you have to consume them in the right ratios.

Long-chain Omega-3 fatty acids (found in wild-caught fish and game, flaxseed, etc.) and Omega-6 fatty acids (found in eggs, nuts, grains and grain-fed animals) are both good for you. But too much Omega-6 relative to Omega-3 triggers inflammation and concomitant health problems. Before agriculture came on the scene, humans naturally ate a 1:1 ratio of Omega-6 fatty acids to Omega-3 fatty acids. But in modern Western societies, the ratio's now skewed to anywhere from 10:1 to 30:1. We are, in other words, way out of whack.
So what can we do about this? Try to steer away from grain-fed meats and towards grass-fed meats, and take in more Omega-3s. (I eat sardines and/or supplement with fish oil.) And limit or eliminate high-Omega-6 foods from your diet, including vegetable/canola oil, soybean oil, corn oil, and peanuts.
  • Trans Fats
Avoid trans fats. They suck. Check nutrition labels for the trans fat content. And if the ingredients include anything starting with the words "partially hydrogenated" or "hydrogenated," don't touch it with a ten-foot pole. And if you're still dipping into tubs of margarine, you need to wake the hell up.

Q: Whoa. Back up. You said to avoid vegetable oil? That’s crazy talk. Everyone knows you’re supposed to cook with vegetable oil.

A: Let me just say this: Your vegetable oil is killing you. Throw it away.


Q: Okay, okay. This is getting super-boring. Enough with the science behind low-carb/high-fat diets. What does this have to do with why you’re eating Paleo?

A: Simply put, I eat Paleo because it’s the approach that’s most consistent with all the stuff I’ve discussed above.

As I mentioned above, applying principles of evolutionary biology, Paleo adherents point out that human genetics haven’t changed since before the dawn of agriculture, and therefore, the optimum diet for modern humans is still the same one that hunter-gatherers were evolved to eat. Anatomically modern humans have been on the planet for at least 200,000 years. Before agriculture arrived on the scene a mere 10,000 years ago, every person on the planet ate whole foods that they hunted or gathered: meat, seafood, plants -- all of 'em stuffed with the nutrients necessary for and beneficial to health. (Recent archaelogical findings suggest that our ancestors were butchering and eating meat and bone marrow as much as 800,000 years ago.)

As agriculture has spread -- now, to the point of cramming corn, wheat and soy-derived products into just about anything that's even remotely edible -- so has the superfluous intake of carbohydrates and sugar. The Standard American Diet (S.A.D. for short) is comprised mostly of Neolithic foods with significant carb content. And as discussed (super-boringly) above, there's strong evidence that high-carb (a.k.a. low-fat) diets are bad news.
Plus, recent studies have found that eating Paleo is better for you than even the much-ballyhooed (i.e., massively overhyped) "Mediterranean diet." (Don't get me started on the Mediterranean diet.)

Q: At least I’ve heard of the Mediterranean Diet. This Paleo business still sounds intense and weird. What made you start eating like such a freak?

A: In 2009, I happened upon Mark Sisson’s website, Mark’s Daily Apple, and started reading about his Primal Blueprint approach to eating and exercise. It sounded weird, and I wasn't sold on his no-grains-or-legumes message. But I was intrigued enough to seek out more information about ancestral eating habits -- the way people were hard-wired to eat for the vast majority of human history, until agriculture came on the scene a scant 10,000 years ago. Upon further digging, I found Gary Taubes’ “Good Calories, Bad Calories” and Loren Cordain’s “The Paleo Diet,” and decided to give this approach a shot. (Taubes' book isn’t marketed as a "Paleo" guide per se, but it makes a strong case for eating an ancestral diet that eschews Neolithic foods like grains and other processed stuff.)

I found Paleo eating to be intuitive and appealing on a number of levels. First of all, the concept resonated with me the same way that running barefoot did. After all, over the course of two hundred thousand years, we evolved to eat stuff that we could hunt and gather: meat and vegetables -- and somehow, the human race managed to survive and thrive without pounding down bowls of Wheaties and spaghetti. (Similarly, we managed to get around just fine without the benefit of super-cushioned motion-control Nike running shoes.)

It also helped to know that I wasn't alone. Not long after transitioning to this new eating approach, I joined a CrossFit gym, where I've met others who eat Paleo -- not surprising, given that CrossFit -- via Robb Wolf -- is largely responsible for the phenomenal growth of the Paleo movement. (A ton of other CrossFitters swear by Barry Sears' Zone diet, which requires weighing and measuring the nutrient components of what you eat, but doesn't take food quality into account. I suspect, though, that the Zone's nothing more than a marketing gimmick that happens to work moderately well because it recommends some reduction in carb intake. Something's better than nothing, I suppose, but I'm self-aware enough to know that I'm too lazy to carefully track and calculate my food intake day after day.)

But most importantly, going Paleo meant I didn't have to starve myself in order to maintain my weight and body composition. I didn't have to weigh or measure what I ate, obsessively count calories, or lug around a food log. By focusing on food quality and eating meat and vegetables, I can eat to satiety and not worry about going overboard.

Q: But I bet you've become horribly fat and unhealthy since going Paleo, right?

A: Actually, my lab resultsbody composition tests and gym performance are just fine and dandy, thankyouverymuch.

Despite eating a ton of stuff that the "experts" say to avoid, my HDL level (100) is through the roof. As Oprah-drone Dr. Mehmet Oz put it: "[T]here has never been a heart attack or lack of blood flow stroke reported in the entire medical literature with a functional HDL over 100."

Plus, my body composition has significantly improved. A recent DEXA scan shows that I have 9 percent body fat, which puts me in the first percentile among guys my age (meaning that I now have less body fat than 99 percent of all men in their mid-30s).

As for athletic performance, my Olympic lifting continues to improve, and I'm still setting PRs in CrossFit. So far, so good.


Q: Didn't cavemen die by the age of 30 or something? Doesn't this suggest that their diets were crap?

A: Prehistoric humans certainly had shorter lifespans on average. (Butonly by about 10 years, actually.) What drove down their average number of years on earth? Hmm. Let's see: High rates of infant mortality, zero medical care, a perilous existence in the wild, predators, accidents, trauma -- the list goes on and on, though it probably doesn't include Type II diabetes. (I wonder how long we'd last if we were dumped in the middle of the woods without our cell phones and pants. I'd give myself a day and a half. And that's only if I had a good book and a Snuggie with me.)

Look: If 40 out of 100 cave-babies died before reaching the age of 10, even if every one of the survivors lived past the age of 60, the average age expectancy of the group will fall under 40 years.

The thing is, plenty of studies have been done about the longevity of modern day hunter-gatherer societies. As Loren Cordain has written:
In most hunter-gatherer populations today, approximately 10-20% of the population is 60 years of age or older. These elderly people have been shown to be generally free of the signs and symptoms of chronic disease (obesity, high blood pressure, high cholesterol levels) that universally afflict the elderly in western societies. When these people adopt western diets, their health declines and they begin to exhibit signs and symptoms of "diseases of civilization."
In fact, societies that adopted widespread agricultural practices have shown "a marked decline in health indicators," from shortened stature and degenerative bone conditions to skull deformities, dental problems, and increased infection risks. When agriculture was introduced to human societies, average life expectancy actually got shorter, not longer.

Q: But cavemen ate meat! And eating meat is evil and immoral! It's not environmentally sustainable! And it's totally unhealthy!

A: Sheesh. A whole book could be written in rebuttal to those three points. Luckily, pepper-pie victim and ex-vegan Lierre Keith has done just the thing. You can preview it (i.e., read the whole thing) on Google Books here. Pay special attention to Chapter 4, which is a response to "nutritional vegetarians" -- i.e., vegetarians who claim that eschewing meat puts you on the road to better health.

Keith also counters the moral/ethical arguments that are often raised against meat-eating -- a topic that other authors have also addressed. We can all agree that factory farming is evil and unsustainable, but even prominent pro-vegans like George Monbiot have finally come around to concede that meat-eating contributes to a healthy ecosystem. (Check out Monbiot's Guardian column here.)

Look: I love vegetables. I think everyone should eat 'em 'cause they're tasty and awesome. But eating good quality meats is important, too.

Q: But humans can't digest meat! It just sits in your gut and rots 'til you poop it out!

A: You're wrong. So, so wrong.
Q: What about the China Study, which concludes that a low-fat, vegetarian diet is healthiest for humans, and eating meat causes cancer?

A: Like Ancel Keys' Seven Countries Study, T. Colin Campbell's 2005 book, "The China Study," underpins an entire movement -- but it's beenexhaustively debunked. Raw Food SOS's Denise Minger systematically tore it apart, point by point. Campbell evidently couldn't (or wouldn't) distinguish between correlation and causation, and made pronouncements based on correlations that don't even exist in the underlying data that he cites from observational studies. The popular media hasn’t yet caught on, but science has called bullshit on "The China Study."

Despite the fact that vegetarians and health journalists often blithely cite to Campbell's conclusions without bothering to but on their thinking caps, and contrary to overhyped news reports and fitness magazine fluff pieces, there are in fact no valid studies proving that a vegetarian diet is better for human health than a non-vegetarian one.

In fact, even after Campbell agreed to debate Loren Cordain, Campbell himself ended up citing a grand total of zero studies in support of his "meat causes cancer" hypothesis. Instead of pointing to any actual evidence, the best he could do was to refer to his own "philosophy of nutrition." Seriously?

Q: What about soy? I know it's a legume, but we all know how healthy it is -- especially relative to meat.

Q: But my DOCTOR says low-fat diets are best.

A: Have you ever considered whether your doctor is even qualified to weigh in on this subject? We have a good number of friends and family members who are super-awesome doctors, but I think few (if any) of them would consider themselves to be nutrition experts. In fact, most doctors know relatively little about nutrition. They don’t have to complete much coursework on it during their training, and in fact, "a vast majority of medical schools still fail to meet the minimum recommended 25 hours of instruction" in nutrition.

(My favorite line from the New York Times' recent article about physicians' lack of education about nutrition: "[The doctor] paused for a moment, looked suspiciously around the nursing station, then leaned over and whispered, “I know we’re supposed to know about nutrition and diet, but none of us really does.”)

Still, you should hear out your doctor, and carefully consider the guidance. But if I were you, I wouldn't blindly follow his/her advice without digging deeper, because chances are good that your doctor's just regurgitating the USDA's flawed recommendations and some marketing language pulled from a brochure they got from a drug rep after accepting a free dinner and a case of samples

Use your noggin. That's what it's for.

Q: But humans need carbs to live! How can you work out without loading up on carbs?

A: First of all, I do, in fact, eat carbs. I just get 'em in the form of vegetables and fruit rather than grains, legumes and added sugar. Yes, Paleo eating tends to be relatively low-carb because it eschews grains and sugar, but at its core, this approach to nutrition is actually carb-agnostic. I don't count carbs, nor have I put myself (consciously) on a super low-carb ketogenic diet.

But just so you know, humans don't actually need dietary carbs at all to function and thrive.

In the early part of the 20th century, Arctic explorer Vilhjalmur Stefansson -- after living among the Inuit -- found that he and his fellow explorers suffered zero health problems from eating a hunter-gatherer diet consisting almost exclusively of high-fat meat and fish, and no carbs whatsoever. From Wikipedia:
When medical authorities questioned him on this, he and a fellow explorer agreed to undertake a study under the auspices of the Journal of the American Medical Association to demonstrate that they could eat a 100% meat diet in a closely-observed laboratory setting for the first several weeks, with paid observers for the rest of an entire year. The results were published in the Journal, and both men were perfectly healthy on such a diet, without vitamin supplementation or anything else in their diet except meat.

Stefansson published his thoughts on no-carb eating in Harper's in 1935. You can read his first-person account of carnivorous life among the Inuit here.

So what happens when you take in no carbs? Your body still requires a bit of glucose, but it can manufacture its own out of lactate, pyruvate, glycerol and amino acids (from protein) via a process calledgluconeogenesis. As Lyle McDonald -- a proponent of ketogenic diets -- has said: "[A]s long as protein intake is sufficiently high (e.g. the diet is covering the increased breakdown of protein in the liver and elsewhere), the amount of carbohydrates which are truly required is still zero."

Kurt Harris sums it up nicely:
There are no essential carbohydrates, even for athletes.
Despite current nutritional dogma dating from the 1970's, carbohydrate consumption is completely unnecessary for your energy (or any other) needs. Fat is the primary way we store energy in our bodies, and eating fat is the evolutionarily preferred food source in a food-abundant environment. During aerobic exercise, the predominant fuel source is fatty acids, supplemented by glycogen stores.
It is possible to eat no carbohydrates at all and still do plenty of physical work. Any carbohydrates needed not provided from glycogen or food can be produced in abundance via gluconeogenesis. Glucose provided this way makes you literally burn fat, and keeps your insulin levels low.
You have about about an hour or more of exercise in your liver and muscle glycogen.
If you are a lean runner, you have enough energy in your body fat to walk about 800 miles.
You simply don't need to eat carbohydrates to exercise.
Of course, low- or no-carb diets necessitate eating more protein and fat. But again, contrary to conventional wisdom, that's not a bad thing. In fact, low-carb/high-fat diets -- even the much-maligned Atkins Diet -- have been shown to reduce saturated fat in your blood and markers of inflammation. Plus, they reduce "heart disease risk factors, including lower triglycerides and lower LDL, or 'bad' cholesterol." Plus, compared with low-fat dieters, "[l]ow-carb dieters had greater increases in HDL, the good cholesterol."
Q: Don't you read the news? Scientists have discovered that cavemen ate bread! Ha! IN YO FACE!

A: Granted, there's evidence that the cooking and eating of starchy carbs may date back 30,000 years instead of 10,000 years. But instead of relying on breathless media reports, let's really look at what the researchers found. Melissa McEwen did, and here's what she had to say:
So what's the deal with this study? Now that I'm wormed my way into academia again somehow, I read the paper. They found something that looks like a mortar and pestle with some evidence of starch residues.
The title says flour, but that's not the good old white flour your Aunt Maude is thinking of. Of the nine species mentioned, one is a seed; the rest are roots and rhizomes. That ground starch has been used by humans since the upper Paleolithic is not really news. Famous anthropologist Richard Wrangham who wrote Catching Fire has been writing about the role of cooked starch in the Upper Paleolithic for quite some time. In the Upper Paleolithic it might have spurred population increases that eventually led to early settlements like Gobekli TepeThere has been selection for genes like AMY1 which allow for better starch digestion.
And the paper writers are like HAHA -- look, the carnivorous Atkins people are soooo wrong. But wait. I think isotope studies are a little more accurate than a few -- as the paper admits -- "poorly preserved" plant remains. And the evidence is that thePaleolithic diet was mostly animal protein.
So despite the hyperbolic news articles, let's not kid ourselves: It's not like cavemen were sitting around making pitas and baking bread. They weren't subsisting on grains.

But fine: For the sake of argument, let's say that this so-called "bread" has been part of the human diet for 15 percent of our species' history, and not 5 percent. That still doesn't change the fact that the stuff isn't good for you.

Q: Whatever. All this talk of “cavemen” and “evolution” don’t concern me. I don't believe in any of that stuff.

A: Okay. If you're a strict, anti-Flying Spaghetti Monster Creationist and believe that our planet is just 6,000 years old, you're probably not going to agree with the evolutionary biology underlying the Paleo diet.

But that doesn't mean you can't join the party! There are a bunch of folks out there who've been able to resolve their Creationist beliefs with a Paleo-like approach to eating. Examples can be found here and here. You can also take a gander at Jimmy Moore's post on Christianity and Paleo eating.

Q: This is just another fad diet.

A: Maybe. Time will tell. But I'll bet that the number of people who ate this way throughout the course of human history vastly outnumber the folks who swear by the low-fat dogma of Ancel Keys, which didn’t emerge until the 1950s. (If you take the long view, which one looks more like a fad?)


Q: Do Paleo eaters also avoid sugar and other sweeteners?

A: Duh. Stop eating sugar. And not just ‘cause it’ll rot your teeth and make you fat, insulin-resistant and diabetic -- it may actually be carcinogenic to boot.

Q: What about agave nectar? That stuff’s natural!

A: No, it isn’t. Think agave nectar just comes dripping out of an agave cactus? Think again. And besides, it’s still sugar. Stay away from the stuff.

Q: But I've seen tons of recipes on the Internet for "Paleo pancakes" and "Primal cookies"! They might not contain grains and refined sugar, but they aren't "whole, unprocessed foods," either, right? And plenty of ‘em use sweeteners like maple syrup and honey!

A: You're right. Kurt Harris calls these concoctions "Candy Cigarettes" -- they're psychological crutches that are "designed to look and taste like signal dishes of 19th and 20th century industrially-inspired and manufactured food." As he puts it:
[T]his “paleo food” thing is bogus. If your food needs a prefix, it is not “paleo” in either the historical or the metabolic sense, and it is, more emphatically, not paleo in the sense that it is helping to keep alive the reigning agricultural paradigm – the one that wants our food to look like agricultural food so that we still crave agricultural food. Manufacturing simulacra of grandma’s comfort food in your kitchen is either:
  1. Pointless work to make something awful tasting;
  2. A veiled excuse to make a sugar vehicle; or
  3. An unconscious exercise in the service of Ancel Keys’ Neolithic Food Army Reserve. Keep that big-agra-supplied uniform pressed and hanging in the closet, waiting for the call-up [on] the day when the paleo-pancake is not doing the trick, and hell, why not have just one real pancake?
Look -- I understand the desire to hold on to familiar (and highly-processed) foods as crutches. Heck, I made "Primal" chocolate chip cookies with the kids a while back. But you know what? Harris is right: Just because we used maple syrup -- a “natural,” Paleo-compliant sweetener! -- doesn't mean those cookies weren't just another excuse to ingest sugar.

Say it with me: A sugar is a sugar is a sugar.

Q: What about fruit? Since it's Paleo-approved, can you eat as much of it as you want? Along the same lines, guzzling unlimited quantities of fruit juice is fine, too, right?

A: Not exactly.

Yes, fruit was available to cavemen -- but only seasonally. Before the advent of modern agriculture, food preservation and transportation, fruit (and the fructose within) was really only available in warm months; people ate fruit and fattened up for the winter months.

So while consuming fruit is fine, don't go overboard -- especially if you're still metabolically deranged. Also, try to avoid drinking fruit juices altogether given the high fructose content. (As UCSF Professor Robert Lustig forcefully argues: Fructose = Bad News Bears. Check out the videos of his anti-sugar lecture here.)

Lastly, don't be snookered into believing that it’s A-OK to eat unlimited servings of fruit every day. It’s not. If you’re still sporting a good amount of excess flab, don’t overdo the fruit.

Q: Is it true that Paleo eaters don’t eat white potatoes, but are fine with sweet potatoes? What’s the deal with that?

A: Potatoes are controversial in the Paleo world. Paleo purists shun potatoes because cavemen didn’t eat them. But again, this ain’t about historical reenactment, so who cares?

And frankly, both white potatoes and sweet potatoes are pretty similar from a nutritional standpoint, though sweet potatoes do confer some additional benefits. (For example, they’re chock-full of anti-oxidants, beta-carotene, vitamin C, pro-vitamin E, anthocyanins and sporamins. They also have a lower glycemic index than white potatoes, so they don’t cause as much of a sudden spike in insulin levels.)

The real issue here is that potatoes are super-starchy. The high carbohydrate content in potatoes can derail fat loss plans. So if you’re metabolically deranged (i.e., insulin-resistant and chubbier than you ought to be), you may want to lay off the potatoes -- white or otherwise.

But if you’re not -- you're a lean machine and you’re working out like a demon -- your body’s able to efficiently handle the insulin surges produced when you eat a potato. If you’re in this camp, starchy carbs are great for post-workout refueling and recovery.

For more on the Great Potato Debate, check out this post on Mark’s Daily Apple and this one from Tom Naughton’s blog.

Q: And what about dairy? Do Paleo eaters avoid it completely?

A: I already answered this question above. Pay attention! And readthis) again.

Q: What about booze? Isn’t alcohol supposed to confer health benefits?

A: Good question. My detailed answer’s over here.

But if you’re too lazy to check out that link, here’s what Mark Sisson has to say about alcohol:
I’d suggest skipping the beer (which is liquid grain after all) or in the very least not making it your regular drink of choice. Red wine, with its polyphenols and resveratrol, offers more health bang for your carb allotment. Though Grok didn’t belly up to the bar at the end of the day and strict adherence to the Primal Blueprint would suggest abstaining, life is short. As with any indulgence, it’s best to see it as an occasional rather than regular part of your diet. And keep in mind that some forms of alcohol have less ill effect than going from, say 150 to 250 grams of carbs in a day.
Q: Fine, but you still haven’t given me any reason to avoid grains and legumes other than their high carbohydrate content. Do you hate on grains and legumes just because they make you fat?

A: Not at all. In fact, there are plenty of other reasons to hate on grains and legumes. But at the top of my list of reasons: They have a high anti-nutrient load.

When we eat grains or legumes, we're eating the seeds of plants. And let's face it: these plants don't want their seeds to be eaten.

To ensure the reproduction of their genetic material, these plants have evolved to protect their seeds by -- among other things -- developing compounds that:
  • Resist digestion by predators;
  • Dissolve or increase the permeability of the gut cell linings of predators; and
  • Deliver toxic compounds (like phytic acid and lectins) once the cell linings are breached.
(Don't believe that these anti-nutrients can lead to a leaky gut, inflammation and a host of other health problems? Want to look over the science for yourself? Then read this. And this. And this.)

The effects of anti-nutrients can be somewhat blunted through fermentation or sprouting, but why go through all that trouble when you can just avoid the stuff altogether? After all, grains and legumes don't give you much nutritional bang for the buck, so why waste time/energy/money processing and consuming them?

Oh, right: They're cheap and addictive.

Q: Okay -- Maybe I'll concede that simple, processed grains are unhealthy. But what about whole grains?

A: Whole grains are just empty calories, and they're just as carb-tastic as their more refined cousins. Plus, they're still loaded with anti-nutrients. Even the grain products that are (artificially) fortified with vitamins aren't nearly as nutrient-dense as fruits, vegetables, eggs or meat.

I'm not going to do this subject any justice (and I'm tired of typing), so just read this and this and this.

Even if you can't accept that whole grains should be avoided, I think we can all probably agree that grains of any kind are just vehicles with which to deliver other, more delicious foods -- some of which are good for you, but many of which are not. Think about it: How often do you eat waffles or pancakes without syrup, whipped cream or fruit? Or a dry flour tortilla without cheese or beans or guacamole or salsa? When was the last time you (voluntarily) ate just a slice of plain bread -- with no butter, jam, peanut butter, or spread? Without accompanying a cup of soup or a plate of salad? And without using it to soak up the deliciousness at the bottom of your bowl of spaghetti?

Q: But grains feed the world!

A: True. Grains have enabled the human race to be fruitful and multiply -- so much so that we now dominate the globe. The human empire has been built on agriculture. And now, without grains, most of the six billion-plus people on our planet would surely starve. Over the course of the past 10,000 years, we've become utterly dependent on grains.

So yes, humans have become reliant on agriculture as a source of cheap, plentiful calories. But that doesn't mean grains aren't poisoning us all the same.

As Jared Diamond has written agriculture is "the worst mistake in the history of the human race":
To science we owe dramatic changes in our smug self-image. Astronomy taught us that our Earth isn't the center of the universe but merely one of billions of heavenly bodies. From biology we learned that we weren't specially created by God but evolved along with millions of other species. Now archaeology is demolishing another sacred belief: that human history over the past million years has been a long tale of progress. In particular, recent discoveries suggest that the adoption of agriculture, supposedly our most decisive step toward a better life, was in many ways a catastrophe from which we have never recovered. With agriculture came the gross social and sexual inequality, the disease and despotism, that curse our existence.
Seriously, folks: With the dawn of agriculture, humans got shorter, weaker, and sicker.

What's done is done. (Good thing, too, because there's a pretty good chance you and I wouldn't be here if it weren't for agriculture.) And grains are certainly still a basic necessity of life for many in developing countries who are struggling to eat enough calories to stay alive.

But let’s face it: Grains are simply not a necessity in developed western countries, and certainly not in the U.S. Yes, lots of grain products are super-cheap -- in large part due to the perverse incentives created by insane government policies and agricultural subsidies. But real food isn't more expensive than the carby, processed junk on supermarket shelves. Being a locavore won't bankrupt you -- even if you forego the grains. Heck, even Wal-Mart is selling organic producethese days. And if you’re reading this on a computer screen, you have access to an Internet connection, which means it is highly likely that you have the means to purchase and eat real food. Fritos are not your only option.

Still not convinced? Check out Balanced Bites' advice on eating Paleo on a budget.


Q: Fine. I get that sugar, grains and legumes aren’t great for me. But I’ll just cut down a little. “Everything in moderation,” right?

A: Not for me. I’m eating to optimize my health -- not to settle for mediocre health. Read this post by Craig Zielinski -- it perfectly (and profanely) articulates my feelings on the topic.

Q: You're writing as if “going Paleo” is a no-brainer. So why aren't more people eating this way?

A: Because processed foods -- including grains and sweeteners -- are cheap and addictive. Also: Inertia. Bad science. Money. Marketing. Sloppy reporting. Government support. Lazy thinking. And the insidious effects of confirmation bias clouding the ability of people to recognize Occam's Razor, which holds that the simplest explanation is usually the correct one.

There's a great anecdote in Michael and Mary Dan Eades' "Protein Power Lifeplan":
When a group of scientists evaluated the changing dietary patterns in Spain over the past twenty-five years, they found that the consumption of bread decreased, the consumption of fruits and vegetables decreased, and the consumption of even olive oil decreased. (L. Serra-Mejam et al., “How Could Changes in Diet Explain Changes in Coronary Heart Disease Mortality in Spain? The Spanish Paradox,” American Journal of Clinical Nutrition 61, suppl. 6 (June 1995): 1351s-1359s.) Over the same time, Spaniards increased their consumption of dairy products and meat of all kinds. In other words, the diet of the average Spaniard -- at least by our misguided modern nutritional standards -- degenerated; he ate more high-fat foods of animal origin, while at the same time low-fat, high-carbohydrate foods went lacking. According to the prevailing paradigm of what good nutrition is (again, misguided in our opinion), people throughout Spain should be dropping like flies from cardiovascular disease. What the researchers found, however, was that the rates of death from heart disease declined dramatically over this period.
Since this didn’t fit with what the researchers expected to find, they, as all good researchers do, tried to find some way to reconcile their data with what they “knew” to be true. They reckoned that perhaps some isolated areas of Spain contained unenlightened people who ate a lot of meat, fat, and dairy products, fouling up the statistics for the rest of the country. And when they did evaluate consumption on a region-by-region basis they found exactly that, but unfortunately for their hypothesis, the high-meat-eating regions had the greatest declines in the rates of death from heart disease.
In their words, “it is also paradoxical that regions demonstrating the highest increases in fat intake displayed the lowest rates of CHD [coronary heart disease] mortality.” So uncooperative were their data that these researchers wrote the whole thing off as a quirk and called it the Spanish Paradox.
The Spanish Paradox isn't the only one: Researchers have also identified a French Paradox and an Inuit Paradox and an Israeli Paradox and an Atkins Diet Paradox and countless others. Given that Americans' waistlines have kept expanding despite significantly reducing their dietary fat intake, I suppose we have ourselves an "American Paradox," too.

As these examples pile up, at what point do they stop being viewed as "paradoxes" and start being seen as evidence of an altogether different and incompatible theory?

Answer: When people decide to totally dump the old one.

In “The Structure of Scientific Revolutions,” Thomas Kuhn argues that advances in science don’t occur through steady and gradual falsification of old theories. It’s not like everyone thought the world was flat, and over time, people came to believe that the earth was incrementally curvier and curvier until eventually, it was decided that our planet is round. Science doesn’t progress via an orderly accumulation of facts and evidence; instead, it develops in radical, sudden lurches forward. Paradigm shifts happen.

Why? Fans of the status quo have difficulty accepting new theories because they defy their longstanding and well-established beliefs. Just like the researchers who wrote off the decline in heart disease-related deaths in meat-loving Spain as nothing more than a “paradox,” the vast majority of scientists have repeatedly dismissed compelling evidence that a low-fat diet is unhealthy because they’re unwilling to scrap everything they’ve come to believe. To move forward, the wholesale rejection of an entire existing framework of belief is required.

I've rejected it. The question is: Now that you’ve spent all this time reading this, will you?

Q: Depends. How hard is it to transition to a Paleo diet?

A: Granted, switching to a caveman diet isn't always easy. Due to the sudden drop-off in dietary carbohydrates, folks who are used to mainlining carbs often report that they "feel like shit" for the first couple of weeks after going strict Paleo, as their bodies make the shift from sugar-burning to fat-burning. But if newbies can make it through this initial period of sluggishness (which can last two or three weeks), they typically come through the other end of the tunnel feeling pretty damned good.

That’s why most Paleo diet plans recommend giving it at least 30 days before considering whether to quit. There are tons of month-long plans out there, from Robb Wolf’s to Whole 9’s to CrossFit Love’s. All of ‘em are pretty similar. Start by cleaning out your fridge, going shopping for Paleo goodies, and doing some cooking.

For me, the transition wasn't too bad. Following popular nutrition advice, I'd already been avoiding refined grain products like white bread and rice. (But not pizza. Pizza remained my kryptonite for quite some time.)

Now, I just eat according to five simple rules:
  1. Eat real food.
  2. Eat meat, vegetables & good fat.
  3. Don't overdo nuts & fruit.
  4. Don't eat stuff that hurts you, like gluten-packed grains & legumes.
  5. Before you cheat, ask yourself: Is it worth it?
Q: Not so fast. There’s no way I could give up grains, legumes, sugar and dairy all at once. How can anyone with functioning taste buds ever manage to switch to a Paleo diet?

A: You’d be surprised. If my wife, a foodie who has always gone to extraordinary lengths to eat well, can manage to get through a 30-day Paleo challenge, I’m pretty sure you can, too.

But if going cold turkey isn’t your thing, then take baby steps. Transition to Paleo by removing one bad thing first, and then another, and then another. You’ll be Paleo in no time.

Q: No grains, beans or sugar? If I eliminate all those foods, the only stuff left is bound to be totally bland, vile, or both.

A: Bullshit.

First of all, if you think Paleo food is bland, it’s probably ‘cause you’re not thinking about the tastiest macronutrient of all: Fat.

AND YOU MUST EAT FAT. (The right kinds, of course.)

“Low-fat Paleo” doesn’t work. You’ll wind up hungry, tired and miserable -- and you’ll abandon the diet without ever actually having been on it. Remember: Fat is not poison. It’s your fuel.

With that in mind, there are plenty of awesome Paleo options out there. Here's just one typical week's worth of Paleo-friendly food that I consumed -- not all that weird or disgusting, right?

Also, my wife obsessively documents just about every meal we eat on her Paleo food blog. If you want to see for yourself what you can eat on a caveman diet, check out all the food porn and recipes on her site. She’s even provided a day-by-day rundown of everything she ate on her 30-day Paleo challenge – and I can vouch that none of it was remotely close to “bland” or “vile.” See for yourself.

Q: Hold on. Who says I want to be like you and your wife? You talk about not wanting to tell your dining companions about eating Paleo, but you just wrote 50 pages about it. In fact, I bet you act like a total ass at restaurants. You probably annoy servers with your weird caveman requests and then sit there with a smirk on your face, passing judgment on others for tucking into their bowls of delicious pasta and ice cream. 

A: Not true. (Except the part about being kind of annoying to restaurant workers.) I don’t preach (or even talk) about my caveman diet. Unless someone asks, I don't bring it up. None of my co-workers have any inkling that I eat this way. Although a few friends and family members have become aware of our newfound Paleo-ness (and occasionally pepper us with questions over the dinner table) I'm reluctant to get into deep discussions about it precisely because I don't like being scrutinized while I'm eating -- and I don't want others to feel self-conscious about what they eat in our presence. Besides, I'm aware that diet -- like religion and politics -- is a topic that's best avoided unless one is itching for a fight.

I have a number of friends who are committed to strict calorie-counting as a weight loss strategy, and I know plenty of others who've adopted the "everything in moderation" approach to eating. Some still look to egg-white omelets and low-fat (but high-sugar) cookies for weight loss purposes. If they're happy with those approaches, then that’s their choice. I’m not going to force-feed them grass-fed beef. (I’m saving that stuff for me!)

Q: I can't believe I just wasted my time reading this. Your brain is clearly weak from lack of carbs, and your cholesterol level's probably through the roof. You're going to get incredibly fat and drop dead of a heart attack any day now. Plus, you're condoning the slaughter of animals and the spoliation of our environment. I don't need to read any studies to know you're barking up the wrong tree. A bazillion doctors/nutritionists/food marketers/vegans/bloggers/celebrity trainers/glossy magazines/television commercials have told me to stick to a low-fat, high carb diet, and they can't all be biased or wrong. They're also a hell of a lot smarter and way more credentialed than you. So shut it, loser.

A: Does this mean you don't want to hear what I have to say about the benefits of intermittent fasting?

No comments:

Post a Comment