Is paleo diet healthy?

A few years back, the Paleo diet was the coolest thing since sliced bread. (Literally: You can’t eat grains, dairy products, or legumes on it.) But as far as Google Trends is concerned, the eating plan—which advocates consuming what humans supposedly ate way back in the day, before big agriculture and processed foods—reached its peak interest level at the beginning of 2014 and has been waning ever since—with interest spiking every January after the holiday season.

Despite this seeming decline, Paleo is still a big part of the healthy eating world. Companies continue to make and market products for Paleo eaters, from Primal Kitchen’s Paleo mayonnaise to Purely Elizabeth’s grain-free granola. There’s a Paleo Magazine and dozens of Paleo-focused podcasts, all catering to the interests of caveman-imitating eaters. Many nutrition experts, such as Parsley Health founder Robin Berzin, MD, and science journalist Max Lugavere, continue to promote the eating plan and follow a version of it themselves. It begs the question: What’s going on with the former wunderkind of healthy eating plans?

Some of the flip-flopping around Paleo is part of the natural cycle of diet trends, says Lauren Harris-Pincus, MS, RDN, author of The Protein-Packed Breakfast Club: People try them, then move on. “I’m always skeptical of something that is a trendy, popular diet, because there’s a reason why it trends, and usually that’s because it’s just a new way of repackaging restrictions of some kind that promise weight loss or health benefits,” she says.

“In the case of Paleo, the interest that I saw peaked several years ago, and now I’m getting more questions about the keto diet,” adds Jennifer Bruning, MS, RDN, LDN, a spokesperson for the Academy of Nutrition and Dietetics. She says people seem to largely understand the main principles of the diet: prioritizing grass-fed, ethically sourced meat, leafy green vegetables, and healthy fats; nixing dairy, legumes, and grains; eating way less processed food. “I get a lot of questions regarding the difference between . I think people feel like they have something of an understanding of Paleo, but they’re not sure about how keto compares under this umbrella term of low-carb diets.”

There have also been some doubts about whether the Paleo diet is healthy. In January, US News and World Reports ranked the Paleo diet No. 33 (tied with the Fast Diet) on its list of the 41 best diets overall, writing, “Experts took issue with the Paleo diet on every measure. Regardless of the goal—weight loss, heart health or finding a diet that’s easy to follow—most experts concluded that it would be better for dieters to look elsewhere.” More recently, a study from Australian researchers published in June found that following the Paleo diet long-term was associated with increased risk factors for heart disease. (FWIW, this was a small study on only 44 people that contradicts the findings of previous studies, so more research is absolutely needed.) Some research has even suggested that the plan’s interpretation of how Paleolithic-era people ate is totally off-base.

For the record, both Bruning and Harris-Pincus typically recommend less restrictive eating plans. “I also don’t eliminate entire food groups, ever, unless there’s an allergy or strong medical reason,” says Harris-Pincus—an issue she has with Paleo-style eating.

Everything to know about the Paleo diet superstar, the sweet potato:

Despite this, Paleo is hardly a relic of the past, as proved just by a visit to the grocery store. Throw a stone in Whole Foods and you’ll find grain-free crackers, bars, and cereals; a whole nut butter category beyond peanuts; Paleo-friendly protein powders and jerkys; even Paleo condiments. Yet the plethora of packaged options comes with its own set of downsides. “For some folks, having those bars and snacks and things like that available to them is very helpful, and to others, they may reject that as being fundamentally not part of the initial idea of the Paleo diet,” says Bruning—which originally focused on moving away from processed foods to more whole foods available to hunger-gatherers, she says.

Certain core tentpoles of Paleo—like eating ethically sourced animal products and cutting back on refined sugars—have inspired direct offshoots. Take the pegan diet, which was first coined in a 2014 blog post by Mark Hyman, MD, director of the Cleveland Clinic’s Center for Functional Medicine. In the post, Dr. Hyman wrote that he took the best aspects of the Paleo and vegan diets—which “both focus on real, whole, fresh food that is sustainably raised”—to make one eating plan that he feels is super beneficial. It also has some room for flexibility; for example, one can incorporate animal-based protein sources or make it completely vegan, Dr. Hyman previously told Well+Good. This iteration of the Paleo diet still has a following: In December, Pinterest named “going pegan” one of its 100 Pinterest trends for 2019.

Going forward, Bruning says she’s going to pay attention to how the traditional Paleo diet fares as climate-focused diets continue to enter the mainstream. (Remember, the eating plan has long emphasized animal proteins.) “I think it’ll be interesting to watch in coming years to see how competition from an increase in things like plant-forward eating, environmental concerns, and some various groups that have made statements about what a healthful diet for the body and the planet may look like,” she says.

In Dr. Hyman’s view, environmentalism and Paleo/pegan eating aren’t mutually exclusive. Five years out from that blog post, he says that’s still how he eats. He adds that, now, whenever he can, he aims to eat meat that’s been raised regeneratively—meaning that the farm used a certain set of practices that prioritize soil health in order to reduce carbon impact and improve water quality. “Even if you eat organic or if you eat grass-finished meat, it may not be in a way that’s produced that’s good for the environment, good for climate, good for animals, for the planet,” he says. It’s one shift that could help move Paleo-inspired eating into the future.

So yes, maybe people have overlooked the Paleo diet for keto and intermittent fasting and all of the other numerous hot eating plans that have popped up in the last five years. But it continues to make a mark on wellness that likely isn’t going away any time soon.

Want to learn more about the Paleo diet? Here’s how it compares to Whole30. And here’s what it means when people talk about “primal” eating.


How safe is the Paleo diet?

Scientists have warned against following celebrities into “fad” diets that are not supported by scientific evidence, as findings published in the journal Nutrition and Diabetes reveal that just 8 weeks on the “Paleo” diet can pile on the pounds and raise the risk of health problems.

Share on PinterestThe researchers say on a ‘Paleo’ diet gained 15% of their body weight in less than 2 months.
Image credit: University of Melbourne

Mass media hype, including celebrity chefs, the tabloids and reality TV shows, are encouraging growing numbers of people to try this and other diets, despite the lack of evidence regarding health benefits. In 2014, the Paleo diet was the most searched-for diet on the Internet.

Adherents of the LCHF diet consume more protein, fiber and fat than the average Western diet and less sugar and starchy carbohydrates.

Suggested “dos” include grass-produced meats, fish or seafood, fresh fruits and vegetables, eggs, nuts and seeds, and healthful oils such as olive, walnut, flaxseed, macadamia, avocado and coconut.

Foods to avoid include cereal grains, legumes – including peanuts – dairy products, refined sugar, potatoes, processed foods, salt and refined vegetable oils.

Risks of weight gain and diabetes with LCHF diet

Switching from processed foods and refined sugars to more fruit and vegetables can help achieve weight loss, and a lower carbohydrate intake also means less chance of blood glucose levels rising after a meal.

However, the pounds will not automatically fall off with an LCHF diet. Moreover, high dietary fat, regardless of body weight, can cause lipids to accumulate in the liver, limiting the ability of insulin to deal with hepatic glucose production.

Researchers at the University of Melbourne were concerned about the hazards of a paleo diet, especially for those who are already overweight and living a sedentary lifestyle and for individuals with pre-diabetes or diabetes.

To investigate, they took two groups of overweight mice with symptoms of pre-diabetes.

The mice in one group consumed an LCHF diet for 8 weeks, 60% of which was fat, compared with their usual 3% fat intake. Carbohydrates made up 20%. The mice in the control group ate their usual food.

The report states that after 8 weeks, the Paleo diet group had increased in weight, glucose intolerance and insulin. The mice had gained 15% of their body weight, and their fat mass had doubled from 2% to almost 4%.

This “extreme weight gain” is equivalent to a person who weighs 200 pounds gaining 30 pounds in 2 months.

It increases the risk of high blood pressure, bone problems, arthritis, anxiety and depression, and potentially high blood sugar, elevated insulin levels and ultimately diabetes.

The bottom line, says lead author Assoc. Prof. Sof Andrikopoulos, is that eating too much fat is not good.

Assoc. Prof. Andrikopoulos, who is also president of the Australian Diabetes Society, concludes:

“There is a very important public health message here. You need to be very careful with fad diets, always seek professional advice for weight management and always aim for diets backed by evidence.”

Instead, he recommends the Mediterranean diet for people with pre-diabetes or diabetes, because, he says, “It is backed by evidence and is a low-refined sugar diet with healthy oils and fats from fish and extra virgin olive oil, legumes and protein.”

Medical News Today recently reported on research that asks what ancient people really did eat.

The Paleo problem: Examining the pros and cons of the Paleo Diet.

Unless you’ve been living in an actual cave, you’ve probably heard all about the Paleo – or “caveman” – diet. Maybe you’ve even tried it. A little meat here, some fresh veggies there. Perhaps going grain- or processed-food-free. It’s a cool idea that captures the imagination. But is it healthy? And does it work? That’s what we’ll explore in this article.

What we’ll cover

In this article, we’ll give you a definitive guide to the Paleo diet.


  • We’ll define just what “Paleo” refers to.
  • We’ll explain what’s so special about hunter-gatherers.
  • We’ll review how and what ancestral-style eaters actually do.

Then, we’ll explore the ideas and evidence critically.

  • What does Paleo promise?
  • What evidence supports ancestral-style eating?
  • What might cause our chronic 21st century health problems?
  • Is the Paleo diet truly primal?
  • What does our GI tract tell us?

Finally, we’ll give you the all-important conclusion:

  • What should YOU do with all of this?

“Paleo” defined

The Paleo, or primal, diet is based on two central ideas.

  1. We adapted to eat particular kinds of foods.
  2. To stay healthy, strong, and fit — and avoid the chronic diseases of modernity — we need to eat like our ancestors.

A brief history of eating

Our oldest cousins, the earliest primates, lived more than 60 million years ago. And, just like most primates today, they subsisted mainly on fruit, leaves, and insects.

About 2.6 million years ago, at the dawn of the Paleolithic era, things began to change.

Our early human ancestors started rockin’ the opposable thumb and big brain adaptations. They started using stone tools and fire, and, as a result, slowly changed their diet.

By the time truly modern humans came on the scene about 50,000 years ago, our ancestors were eating an omnivorous hunter-gatherer diet.

The basic Paleo diet

And thus we arrive at a model of a Paleo diet that includes:

  • animals (meat, fish, reptiles, insects, etc. — and usually, almost all parts of the animals, including organs, bone marrow, and cartilage)
  • animal products (such as eggs or honey)
  • roots/tubers, leaves, flowers and stems (in other words, vegetables)
  • fruits
  • nuts and seeds that can be eaten raw

Recently, many Paleo proponents have suggested that eaters start with the above, then slowly introduce grass-fed dairy (mostly yogurt and other cultured options), and small amounts of “properly prepared” legumes — meaning legumes that have been soaked overnight.

What’s so special about hunter-gatherers?

About 10,000 years ago, most of the world figured out agriculture. And thus, we moved from the Paleolithic to the Neolithic period.

Planting and farming provided us with a consistent and relatively reliable food supply, without which civilization could never have developed.

Yet the 10,000-year time frame since the dawn of the Neolithic period represents only about 1% of the time that we humans have been on earth.

Many people believe that the change from a hunting and gathering diet (rich in wild fruits and vegetables) to an agricultural diet (rich in cereal grains) gave rise to our modern chronic diseases such as obesity, diabetes, and cardiovascular disease.

This is a fundamental tenet of the Paleo Diet, and a big reason why proponents say we should return to the meat and produce-based diet of our past.

How do “ancestral eaters” fare?

Of course, while we have extensive skeletal remains, cooking sites, and other types of evidence, we don’t have detailed medical records of our hunter-gatherer hominid ancestors.

However, we do have real live sample populations that we can look at.

A diverse dietary world

The very few surviving hunter-gatherer populations subsist on a wide variety of diets, from the “nutty and seedy” African !Kung, to the root vegetable-eating Kitavans near Papua, New Guinea, and the meat and fat-loving Inuit of the Arctic.

These foraging diets are diverse and probably reflect the widely varying diets of our prehistoric ancestors, simply because what people ate depended on where they lived: mostly plant-based (in the tropics), mostly animal-based (in the Arctic), and everything in between.

However varied their diets across the globe, most Paleolithic humans likely consumed about three times more produce than the typical American.

And when compared to the average American today, Paleolithic humans ate more fiber, protein, omega-3 fatty acids, unsaturated fat, vitamins and minerals, and much less saturated fat and sodium.

Image source: Jen Christiansen (Scientific American)

A modern example

The residents of Kitava Island, off Papua, New Guinea, are probably the most famously researched modern hunter-gatherer population.

According to Dr. Staffan Lindeberg, who’s extensively studied their habits, Kitavans live exclusively on:

Kitavans are healthy and robust, free of obesity, diabetes, heart attacks, stroke, and acne — despite the fact that most of them smoke!

Things are looking good for eating like a cave dweller.

What Paleo promises

The main idea of a primal diet — as you’ve probably gathered (no pun intended) — is that our ancient human genetic “blueprint” doesn’t match our current 21st century diet and lifestyle.

As a result, our health and wellbeing suffer.

The Paleo diet also makes some key evolutionary assumptions:

  • Paleolithic hunter-gatherers were robust and healthy; if they didn’t die young from accident or infectious diseases, they lived about as long as we do now.
  • When Paleolithic hunter-gatherers shifted to Neolithic agriculture, they got relatively sicker, shorter, and spindlier.
  • Modern hunter-gatherers are healthy, and their health declines when they switch to a modern diet.

What’s the evidence?

While a case can be made for this evolutionary trend, as a matter of fact, hunter-gatherers were not pristine models of health.

To begin with, they certainly harbored various parasites. They were also subject to many infectious diseases.

What’s more, a recent study in The Lancet looked at 137 mummies from societies ranging all over the world — from Egypt, Peru, the American Southwest, and the Aleutian Islands — to search for signs of atherosclerosis.

They noted probable or definite atherosclerosis in 47 of 137 mummies from all four geographical regions, regardless of whether the people had been farmers or hunter-gatherers, peasants or societal elite.

All got hardening of the arteries, no matter what their lifestyle. In fact, the hunter-gatherers of the Aleutian Islands had the highest prevalence, with 60% of their mummies having evidence of atherosclerosis.

Food for thought.

Diseases of affluence and industrialization

Although atherosclerosis may be a common human experience no matter what, “diseases of affluence” (obesity, diabetes, and cardiovascular diseases) have certainly gone up dramatically in the past 50 years in industrialized countries like the U.S., especially compared to non-industrialized populations.

Over the last century — a period that is undoubtedly far too short for significant genetic adaptation — industrialization and technology have radically changed the way we eat and live.

Today, the average American subsists on foods that are packaged and commercially prepared. Rich in refined sugars and starches, highly processed fats, and sodium, these foods are designed to be so delicious that they run roughshod over the body’s normal fullness signals, and encourage overeating.

Consider: The top six calorie sources in the U.S. diet today are grain-based desserts (cake, cookies, etc.), yeast breads, chicken-based dishes (and you know that doesn’t mean roast chicken), sweetened beverages, pizza, and alcoholic drinks.

These are not ancestral foods. Nor foods that any nutrition expert, regardless of dietary persuasion, would ever recommend.

So when proponents of the Paleo diet claim that our modern Western diet isn’t healthy for us, they are absolutely correct.

But is the Paleo diet really Paleo?

Remember: There’s no single “Paleo diet”.

Our ancestors lived pretty much all over the world, in incredibly diverse environments, eating incredibly diverse diets.

Still, in most cases, primal diets certainly included more vegetables and fruits than most people eat today. So if we want to be healthier, we should do what our ancestors did and eat a lot of those. Correct?

Maybe so… but not necessarily for the reasons that Paleo proponents recommend.

First of all, most modern fruits and vegetables are not like the ones our ancestors ate.

Early fruits and vegetables were often bitter, much smaller, tougher to harvest, and sometimes even toxic.

Over time, we’ve bred plants with the most preferable and enticing traits — the biggest fruits, prettiest colors, sweetest flesh, fewest natural toxins, and largest yields.

We’ve also diversified plant types — creating new cultivars from common origins (such as hundreds of cultivars of potatoes or tomatoes from a few ancestral varieties).

Likewise, most modern animal foods aren’t the same either.

Beef steak (even if grass-fed) is not the same as bison steak or deer meat. And so on.

This doesn’t make modern produce or modern meat inherently good or bad. It’s just different from nearly anything available in Paleolithic times.

So the claim that we should eat a diet rich in vegetables, fruits, and meats because we are evolved to eat precisely those foods is a little bit suspect. The ones we eat today didn’t even exist in Paleolithic times!

Grains and grasses

Proponents of the Paleo diet argue that our ancestors’ diets could not have included a lot of grains, legumes, or dairy foods. And they contend that the past 10,000 years of agriculture isn’t enough time to adapt to these “new” foods.

This argument is compelling but doesn’t stand up to scrutiny.

  • To begin with, recent studies in the Proceedings of the National Academy of Sciences, using more advanced analytical methods, have discovered that ancient humans may have begun eating grasses and cereals before the Paleolithic era even began — up to three or even four million years ago!
  • Further research has revealed granules of grains and cereal grasses on stone stools starting at least 105,000 years ago.
  • Meanwhile, grain granules on grinding tools from all over the world suggest that Paleolithic humans made a widespread practice of turning grains into flour as long as 30,000 years ago.

In other words, the idea that Paleolithic humans never ate grains and cereals appears to be a bit of an exaggeration.

Are beans really bad for you?

Grains are not the only plant type that the Paleo diet typically limits. Advocates also recommend that you avoid legumes (beans, peanuts, peas, lentils) — and for a similar reason.

However, the idea that legumes were not widely available or widely consumed in Paleolithic times — like the argument that humans didn’t eat grains in the Paleolithic era — is false.

In fact, a 2009 review revealed that not only did our Paleolithic ancestors eat legumes, these were actually an important part of their diet! (Even our primate cousins, including chimpanzees, got into the bean-eating act.)

Legumes have been found at Paleolithic sites all over the world, and in some cases were determined to be the dominant type of plant food available. In fact, the evidence for wild legume consumption by Paleolithic humans is as strong as it is for any plant food.

What about anti-nutrients?

Okay. Maybe our ancient ancestors did eat a little bit of grain and some legumes — so the argument from history doesn’t really hold.

But Paleo proponents also offer another reason to avoid these foods: Their high concentration of anti-nutrients, which supposedly reduces their nutritional value to zilch.

There’s just one problem with this argument. It’s wrong.

Indeed, research suggests that the benefits of legumes far outweigh their anti-nutrient content, especially in light of the fact that cooking eliminates most anti-nutrient effects.

Lectins and protease inhibitors, in particular, are greatly reduced with cooking. And once cooked, these chemicals may actually be good for us. Lectins may reduce tumor growth, while protease inhibitors become anti-inflammatory and anti-carcinogenic.

Phytic acid

But what about phytate?

Grains, nuts, and legumes are rich sources of this anti-nutrient, which can bind to minerals such as zinc and iron and prevent their absorption. Surely that, in itself, is enough reason to avoid grains and legumes?

Not necessarily.

While phytic acid can be toxic if we eat too much of it, in more reasonable amounts it actually offers benefits.

For example, it can:

  • have antioxidant activity
  • protect DNA from damage
  • be prebiotic (i.e. bacteria food)
  • have anti-cancer properties
  • reduce bioavailability of heavy metals like cadmium and lead.

And, in a mixed diet composed of other nutrient-dense whole foods, phytic acid is unlikely to cause problems.

In fact, nearly all foods contain anti-nutrients as well as nutrients — particularly plant foods.

For example, incredibly healthy foods such as spinach, Swiss chard, many berries, and dark chocolate are also sources of oxalate, an anti-nutrient that inhibits calcium absorption.

Green tea and red wine contain tannins, another anti-nutrient that inhibits zinc and iron absorption.

And so on.

Overall, phytic acid and other so-called anti-nutrients probably have a “sweet spot” (just like most nutrients).

  • Eating none or a small amount might be inconsequential.
  • Eating a moderate amount might be good.
  • Eating too much will hurt you. (See All About Phytates for more.)

Grains and inflammation

Another argument for a Paleo diet is that eating grains can lead to inflammation and related health problems.

While this can be true for people with celiac disease (about 1% of the population) and for those with non-celiac gluten sensitivity (estimated to be about 10% of the population, if it even truly exists), on the whole, the research does not support this argument any more than it supports the argument about anti-nutrients.

In fact, observational research has suggested that:

  • whole grains may decrease inflammation, but
  • refined grains may increase inflammation.

In other words, it appears that processing may cause problems, not the grain itself.

Meanwhile, controlled trials consistently show that eating grains, whether whole or refined, does not affect inflammation at all!

What can we make of that?

At worst, whole grains appear to be neutral when it comes to inflammation. (See All About Grains and A grain of truth for more.)

And overall, a substantial body of evidence from both observational and controlled trial research suggests that eating whole grains and legumes improves our health, including:

  • improved blood lipids;
  • better blood glucose control;
  • less inflammation; and
  • lower risk of stroke and coronary heart disease.

Eliminating these important foods from our diet to conform to anybody’s dietary ideology is probably a poor idea.

Evolution of the human GI tract

In Paleo circles, it’s sometimes said that while the world has changed in innumerable ways in the last 10,000 years, our genes have changed very little. And further, that we really only thrive in a world with similar conditions to the Paleolithic era.

Quite frankly, this is not how evolution or genetic expression works.

If humans could thrive only in an environment similar to or the same as the ones their ancestors lived in, our species would not have lasted very long.

Examples of the ways we have evolved in the past 10,000 years abound.

For example, over the past 8,000 years or so, about forty per cent of us have developed the capacity to consume dairy for a lifetime. As a species, we’re evolving a mutation whereby we continue to produce the lactase enzyme to break down lactose for far longer periods than our ancestors ever could. True, not everyone can digest lactose well, but more of us can do so than ever before.

And studies have shown that even people who don’t digest lactose well are capable of consuming moderate amounts of dairy, tolerating an average 12 grams of lactose at a time (the amount of lactose in one cup of milk) with few to no symptoms.

Additionally, the emerging science of epigenetics is showing that a “blueprint” alone isn’t enough — genes can be “switched off” or “on” by a variety of physiological and environmental cues.

Gut knowledge

Our digestive systems have adapted over millennia to process a low-energy, nutrient-poor, and presumably high-fiber diet. Meanwhile, Western diets have become high-energy, low-fiber, and high-fat.

Our genes produce only the enzymes necessary to break down starch, simple sugars, most proteins, and fats. They aren’t well adapted to cope with a steady influx of chicken nuggets, Tater Tots, and ice cream.

So how is it that we can still digest our food, albeit imperfectly at times?

Thank the trillions of bacteria that live in our gut. These friendly critters interact with our food in many ways, helping us break down tough plant fibers, releasing bound phytonutrients and anti-oxidants, and assisting us to assimilate many important compounds.

Now, we don’t have direct evidence of which bacterial species thrived in Paleolithic intestines, but we can be pretty confident that our ancestors’ microbial communities would not exactly match our own.

That’s because bacteria evolve and adapt at a rate much faster than our slow human genes. And for us, that’s a good thing.

It helps to explain why, even if the ancient human diet didn’t include grains, legumes, dairy, and other relatively modern agricultural products, we still might thrive on such a diet today – at least, with a little help from our bacterial friends.

The magical microbiome

Thanks to the Human Microbiome Project and other massive research projects around the world, we now know that trillions of microorganisms from thousands of different species inhabit the human body.

In fact, the total genetic makeup of these little creatures is at least 100 times greater than our own! (Essentially, we’re only 1% human. Think about that.)

This vast genetic diversity ensures that our GI tracts can adapt rapidly to changes in diet and lifestyle.

A single meal can change the type of bacteria that populate your gut. And as little as several days on a new diet can lead to dramatic changes in the bacterial populations in your GI tract.

The diverse, complex, and dynamic nature of our microbiome helps to explain why some of us seem to do well on one type of diet, while others will feel and perform better with another type of diet — even though, genetically, we’re all 99% the same!

Many of us can break down the more “modern” food compounds that Paleo advocates claim we do not tolerate well — simply because our intestines harbor bacteria that have evolved to do that job.

For instance, some Japanese people host unique bacteria that can help them digest seaweed.

And many people can alleviate symptoms of lactose intolerance by eating yogurt or other probiotic-rich foods that provide lactose-digesting bacteria.

So even if you don’t naturally break down lactose well, it’s possible, through the right combination of foods and/or probiotic supplements, to persuade the bacteria in your gut to do this job on your behalf.

What’s more, the same strategy could also address gluten intolerance. Recent research shows that some bacteria actually produce enzymes that break down gluten — as well as phytic acid — reducing any inflammatory or anti-nutrient effects.

Which, as we know, are two of the main reasons people recommend starting Paleo diets in the first place.

Modern Paleo research

No matter how you slice it, the Paleo proponents’ evolutionary arguments just don’t hold up.

But that doesn’t mean that the diet itself is necessarily bad.

Maybe it’s a good diet for completely different reasons than they say.

To find out if that is so, a number of researchers have been putting Paleo diets to the test with controlled clinical trials. And so far, the results are promising, though incomplete.

Paleo vs. Mediterranean diets

Perhaps the best known of these researchers is Dr. Lindeberg — the one who also studied the Kitavan Islanders. He and his colleagues have conducted two clinical trials testing the efficacy of the Paleo diet.

In the first, they recruited diabetic and pre-diabetic volunteers with heart disease and placed them on one of two diets:

  1. A “Paleolithic” diet focused on lean meat, fish, fruit, vegetables, starchy root vegetables, eggs, and nuts, or
  2. A “Mediterranean” diet focused on whole grains, low-fat dairy, vegetables, fruit, fish, oils, and margarine.

After 12 weeks, the Mediterranean group lost body fat and saw an improvement in markers of diabetes. Four of the nine participants with diabetic blood sugar levels at the beginning of the study had normal levels by the end. That’s a very good result and must have made the participants happy.

But those in the Paleo group fared even better.

They lost 70 percent more body fat than the Mediterranean group and also normalized their blood sugars. In fact, all ten participants with diabetic blood sugar levels at the beginning of the study reached non-diabetic levels by the end of the study.

By any estimation, that is an astonishing result.

Now, these volunteers were suffering from mild, early cases of diabetes. But a second study of long-term diabetics showed that a Paleo diet didn’t cure them but it did improve their condition significantly.

Other research has found:

  • The Paleo diet is more satiating per calorie than a Mediterranean diet.
  • The Paleo diet improves blood pressure, glucose tolerance, and blood lipids.

However, one caveat: Like most low-carb trials, the macronutrients (especially protein) in these studies weren’t matched.

The Paleo group ate a lot more protein, compared to the other diet groups. Plenty of protein helps keep our lean mass dense and strong, stay lean, and feel satisfied by our meals.

So, we’re not just comparing apples to oranges when protein intakes are different; this is more like comparing grains to goat meat. Literally.

The Paleo diet may indeed be the best plan, but it’s hard to know for sure without direct comparisons that match macronutrients and calories.

Conclusion & recommendations

What does the Paleo diet get right?

Despite the faulty evolutionary theory it’s based on, in the end, the Paleo diet likely gets more right than it gets wrong.

  • Paleo-style eating emphasizes whole foods, lean proteins, vegetables, fruits, nuts, seeds, and other healthy fats, which is a massive improvement over the average Western diet.
  • Paleo-style eating has been extremely effective for improving several chronic diseases. That alone is a huge plus.
  • Paleo-style eating has made us more aware of how processed and crappy a lot of our 21st century food is.

However, we need more rigorous (and carefully matched) trials before we can reach any definitive conclusions.

What are the challenges?

Despite its obvious benefits over the typical Western diet, the Paleo diet has some flaws.

  • The evidence for excluding dairy, legumes, and grains isn’t (yet) strong. So as a nutrition coach, I can’t say it’s a one-size-fits-all prescription. Certainly, some people should avoid dairy and gluten, and keep legume and grain consumption more modest. But most of us can improve the way we look, feel, and perform without completely eliminating these foods.
  • The evolutionary arguments don’t hold up. The human species isn’t simply a collection of adaptations to life in the Paleolithic era. We are an ever-evolving accumulation of inherited characteristics (and microorganisms) that have been switched, reconstructed, lost, and reclaimed since the first prokaryotes came to life on Earth. This evolution has continued over the past 10,000 years — and won’t stop any time soon.
  • In the broader sense, strictly following a list of “good” and “bad” or “allowed” and “not allowed” foods tends to be problematic for most people. Generally, this approach leads to anxiety and all-or-nothing thinking. Maybe it makes us feel more confident and (falsely) sure of ourselves in the short term. But it’s less effective over the long-term — because ultimately, it decreases our consistency.

This may explain why we are seeing the Paleo diet itself evolve.

It’s evolution, baby

Many Paleo advocates have recently come to appreciate and encourage the addition of moderate amounts of starch (albeit a more limited variety of options than I would prefer), as well as some dark chocolate, red wine and non-grain spirits (such as tequila), and grass-fed dairy.

These additions make life much more pleasant. They make healthy eating more attractive and achievable.

In fact, this new “leniency” may partly explain why the Paleo diet continues to gain traction in mainstream nutrition circles.

Because in the end, moderation, sanity and your personal preferences are more important than any specific food list, anti-nutrient avoidance, or evolutionary theory.

What to do today

Consider the good things about ancestral lifestyles. This includes fresh food, fresh air, lots of movement, good sleep, and a strong social network. How could you get just a little bit of these in your life today?

Think about how you could move along the spectrum — from processed 21st century life and food — to choices that are a little more in tune with what your ancient body needs and loves.

Learn a little more about your ancestors. Evolution is cool. Dig into your roots: Where did your people come from? What were their ancestral diets? (23AndMe will tell you how much of your DNA is Neanderthal.)

Keep it simple and sane. Doing a few good things pretty well (like getting a little extra sleep or fresh veggies) is much better than trying to get a lot of things “perfect”.

Stay critical and informed. Avoid dogmatic or cultish thinking. Be skeptical. Look for evidence. Question everything. Primal eating is a super cool idea and may turn out to be more or less right; just keep your late-evolving prefrontal cortex (aka your thinky brain) in the game as you consider all the options.

Help your old body (and your trillions of little buddies) do their jobs. Our bodies are resilient. We didn’t get to be one of the dominant species on the planet by being fussy, delicate flowers. Nevertheless, think about how you can nourish your body optimally in order to give your body and microbiome the best chance of surviving and thriving.

Passionate about nutrition and health?

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What’s it all about?

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Whether you’re already mid-career, or just starting out, the Level 1 Certification is your springboard to a deeper understanding of nutrition, the authority to coach it, and the ability to turn what you know into results.

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We’ll be opening up spots in our next Precision Nutrition Level 1 Certification on Wednesday, April 8th, 2020.

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I’m a huge fan of food. Pizza, watermelon, and craft beer are a few of my favorites.

I’ve also been known to complain about being overweight. I’m 5’7” and wear a size 10 to 12 depending on the brand, but even when I’m at my happiest weight, I comfortably wear a 10. I’ve got hips; what can I say?

But no month-long pizza binge goes unpunished. In September, I purchased a pair of size 10 jeans from my favorite store online that were ~perfect~ for fall.

When they arrived, I realized that I’d either picked the wrong size or I’d officially downed enough beer and pizza to make putting on my go-to size nearly impossible. (Spoiler alert: It was the pizza.)

So, I decided that for 30-straight days, I would dive into the Paleo diet, which bans all forms of dairy, grains, soy, and legumes. I also pledged to drink less and avoid added sugars and artificial sweeteners.

This wasn’t my first clean eating endeavor. I’ve made two attempts at the Whole30 diet (which is basically the Paleo diet with stricter rules). My first trial lasted 10 days and the second attempt lasted 30 (minus eight cheat meals). So I figured 30 days of Paleo would be a walk in the park.

But I invite you to close your eyes and visualize Donald Trump leaning into the mic because boy oh boy was I WRONG!

Here’s what I learned during my month-long journey:

Check out how the host of The Biggest Loser makes the perfect healthy sandwich:

1. Getting all of the facts straight was tough.

The rules for Paleo can be super confusing. I’ll explain more later, but there are a lot of blurred lines on what you can and can’t eat on Paleo. This is probably because there’s no official Paleo authority who defines the guidelines. When I tried the Whole30 diet, I really appreciated that the program had super-rigid rules. If I was ever uncertain about being able to eat a specific food, I could use their guidelines to determine if the food was compliant or not. With Paleo, bloggers and Paleo followers on social media seem to like to make up their own rules, which leads me to my next problem…

RELATED: Gone Paleo? Here’s a Shopping List for Beginners

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Paleo’s going well.

A post shared by Allison Berry (@berryintothis) on Oct 25, 2016 at 9:28am PDT

2. Paleo doesn’t necessarily translate to weight loss.

One Pinterest search for “Paleo desserts” had me scrolling through photos of Paleo cakes and fudge that were technically in line with the diet. But they were also loaded with natural sweeteners, like coconut sugar and maple syrup. I ultimately decided to skip baking Paleo treats.

RELATED: Should You Try ‘The Virgin Diet’ to Lose Weight?

3. Meal prep is my best friend.

Allison Berry

I’m already a fan of making my meals ahead of time since it makes planning what I’m going to eat for the week so easy. So I spent my first Sunday researching recipes, grocery shopping, and cooking meals I knew and loved from my rounds of Whole30. One meal I found myself coming back to throughout the month was this one-pan pesto chicken and veggies recipe that I prepared with a Paleo-friendly pesto. It was a great lunch or dinner option.

After learning that Paleo bacon is a thing (it’s just sugar-free bacon) I made lots of Paleo bacon and asparagus egg cups for weekday breakfasts. It was a nice change from not eating breakfast, ever.

4. You’re on your own when it comes to portion sizes.

Allison Berry

I was surprised that the Paleo diet offered no set recommendation for portions. As long as I stuck to the basic outline, I was free to eat as much as I wanted. This felt kind of like a trap. It didn’t take me long to realize that I was bound to overeat without portion recommendations in place. I tried to keep myself from overdoing it by dividing up Paleo blog recipes into the servings they was supposed to make and stowing the rest away. But when it came to snacking, I often went back for a second apple in the afternoon or an extra serving of veggies and guac.

RELATED: ‘The 4 Mistakes That Sabotaged My Weight-Loss Journey for Years’

5. There’s a blurred line with booze.

From what I can tell, Paleo die-hards don’t want to tell you not to drink. Some sources say it’s fine while others leave the decision up to you entirely. Since no Paleo guru insisted I quit booze, I still ordered cocktails at dinner and said yes to beers with friends after work as usual.

RELATED: 7 No-B.S. Weight Loss Tips That Will Actually Help You Lose Weight

But while my healthy meals left me with more energy and fewer stomachaches, I still hadn’t kicked any bloat by the day 10. So at that point, since my goal was weight loss, not just healthier eating, I decided to stash my corkscrew and banish alcohol in all of its forms for the remaining 20 days.

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Happy rooftop season y’all ✌️

A post shared by Allison Berry (@berryintothis) on Apr 10, 2016 at 4:33pm PDT

Hearst Looking for more tips and tricks? Conquer the paleo diet with ease with the help of The Ultimate Paleo Diet book.


6. Eating out was really frustrating.

Allison Berry

Like, really frustrating. Before date nights with my boyfriend or dinners out with friends, I’d obsessively comb through restaurant menus looking for Paleo options. More often than not I had to plan some substitutions like asking for a different side or to hold the parmesan sprinkle. And even with all of that preparation, the reality of not knowing every single ingredient in my food started driving me crazy. Was the chicken cooked with canola oil? Did my veggies contain any soy? By the time I hit day 15, I’d decided to stick to eating only the food I’d prepared at home for the rest of my experiment.

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7. Saying no to friends got much easier over time.

Allison Berry

Sticking to food I’d prepared for myself meant turning down brunch invitations and staying in on Saturday nights to avoid temptation. It was kind of a bummer, but I started getting used to eating all of my meals at home and grew confident in my ability to make better choices and avoid alcohol. Toward the end of the month, I allowed myself a couple of nights out, but I stuck with drinking seltzer and lime.

RELATED: This One-Day Plan Will Help Jump-Start Your Weight Loss

8. Finding replacements for my favorite foods was possible.

Part of my nightly routine was a snack after dinner. I’d chow down on Pop-Tarts, chips, cheese—you name it, I craved it before bed. I didn’t want to change every part of my daily routine, so I kept myself stocked up on green apples and bananas and snacked on them with a side of almond butter. I was expecting to miss the crazy sugar rush, but was actually surprised to find that my pre-bedtime ritual was a completely mindless process. I could have gotten the same satisfaction from grazing on apples all along. For my post-workout snack, which was usually a protein bar or sugary sports drink, I was able to find a Paleo-friendly protein bar that quickly became a staple on my weekly shopping list.

9. I started seeing results fairly quickly.

Allison Berry

Once I finally stopped drinking, it only took about three days for my waistline to start looking smaller (right around day 13). Toward the end of the experiment my roommate said, “Your face looks skinnier.” Win!

RELATED: 9 Questions That Reveal Whether a Diet Will Work for You

10. My cravings started to disappear.

After a couple of weeks of nixing cheese and grains, I actually got to a point where I wasn’t craving pizza constantly. (Seriously, I craved pizza every day.) I also didn’t miss other junk foods that I’d mindlessly toss into my shopping cart, like bags of chips or blocks of cheese. I’m not saying that I didn’t complain when I could smell free pizza in my office or when I checked my boyfriend’s fridge for snacks and found half a leftover pie from the night before, but I consider the disappearance of my urge for ‘za to be a major accomplishment.

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A post shared by Allison Berry (@berryintothis) on Jun 21, 2016 at 6:09pm PDT

11. My favorite food did not taste quite as amazing after 30 days.

Allison Berry

When I finally made it past 30 full days, I knew my victory meal would be a pepperoni pizza (obviously), plus some pasta to split with my roommate, and a bottle of wine. But even with all the hype, I have to admit that the first bite didn’t taste as amazing as I remembered. I still ate and enjoyed three slices, but the flavor didn’t seem as strong as it had in the past.

RELATED: Exactly How to Use Cheat Days to Lose More Weight

The bottom line: I don’t think that Paleo is an easy fix for losing weight or a lifestyle change that anyone can make quickly, but at the end of my experiment, I lost 3.2 pounds and was able to pull on my jeans without having to shimmy around my room. They were still a smidge tight, but I was happy to see that the waistband wasn’t cutting into my sides. And my roommate seems to be right. If I look in the mirror at the perfect angle, my face does in fact seem to be a bit trimmer.

Since I discovered that I can easily change my eating habits and that it is possible for my tastes to change, I would consider going Paleo again. But I’m not sure this is a realistic way for me to eat every meal (I can’t quit you, cheese). Instead, I’m going to keep up my meal prepping habits so I’ll always have healthy options on hand. I’ve also upped my exercise game (my nemesis) from precisely zero trips to the gym per week to at least four. Oh, and I’m also proud to say that my bed has been and shall remain Pop-Tart-free.

5 Studies on The Paleo Diet – Does it Actually Work?

All of these studies are done in humans and are published in respected, peer-reviewed scientific journals.

1. Lindeberg S, et al. A Palaeolithic diet improves glucose tolerance more than a Mediterranean-like diet in individuals with ischaemic heart disease. Diabetologia, 2007.

Details: 29 men with heart disease and elevated blood sugars or type 2 diabetes, were randomized to either a paleolithic diet (n=14) or a Mediterranean-like diet (n=15). Neither group was calorie restricted.

The main outcomes measured were glucose tolerance, insulin levels, weight and waist circumference. This study went on for 12 weeks.

Glucose Tolerance: The glucose tolerance test measures how quickly glucose is cleared from the blood. It is a marker for insulin resistance and diabetes.

This graph shows the difference between groups. The solid dots are the baseline, the open dots are after 12 weeks on the diet. Paleo group is on the left, control group on the right.

As you can clearly see from the graphs, only the paleo diet group saw a significant improvement in glucose tolerance.

Weight Loss: Both groups lost a significant amount of weight, 5 kg (11 lbs) in the paleo group and 3.8 kg (8.4 lbs) in the control group. However, the difference was not statistically significant between groups.

The paleo diet group had a 5.6 cm (2.2 inches) reduction in waist circumference, compared to 2.9 cm (1.1 inches) in the control group. The difference was statistically significant.

A few important points:

  • The 2-hour Area Under the Curve (AUC) for blood glucose went down by 36% in the paleo group, compared to 7% in the control group.
  • Every patient in the paleo group ended up having normal blood sugars, compared to 7 of 15 patients in the control group.
  • The paleo group ended up eating 451 fewer calories per day (1344 compared to 1795) without intentionally restricting calories or portions.

Conclusion: A paleolithic diet lead to greater improvements in waist circumference and glycemic control, compared to a Mediterranean-like diet.

2. Osterdahl M, et al. Effects of a short-term intervention with a paleolithic diet in healthy volunteers. European Journal of Clinical Nutrition, 2008.

Details: 14 healthy medical students (5 male, 9 female) were instructed to eat a paleolithic diet for 3 weeks. There was no control group.

Other Markers: Systolic blood pressure went down by 3 mmHg.

Conclusion: The individuals lost weight and had a mild reduction in waist circumference and systolic blood pressure.

3. Jonsson T, et al. Beneficial effects of a Paleolithic diet on cardiovascular risk factors in type 2 diabetes: a randomized cross-over pilot study. Cardiovascular Diabetology, 2009.

Details: 13 individuals with type 2 diabetes were placed on either a paleolithic diet or a typical Diabetes diet in a cross-over study. They were on each diet for 3 months at a time.

Weight Loss: On the paleo diet, the participants lost 3 kg (6.6 lbs) more weight and lost 4 cm (1.6 inches) more off of their waistlines, compared to the Diabetes diet.

Other Markers:

  • HbA1c (a marker for 3-month blood sugar levels) decreased by 0,4% more on the paleo diet.
  • HDL increased by 3 mg/dL (0.08 mmol/L) on the paleo diet compared to the Diabetes diet.
  • Triglycerides went down by 35 mg/dL (0.4 mmol/L) on the paleo diet compared to the Diabetes diet.

Conclusion: The paleo diet caused more weight loss and several improvements in cardiovascular risk factors, compared to a Diabetes diet.

4. Frassetto, et al. Metabolic and physiologic improvements from consuming a paleolithic, hunter-gatherer type diet. European Journal of Clinical Nutrition, 2009.

Details: 9 healthy individuals consumed a paleolithic diet for 10 days. Calories were controlled to ensure that they wouldn’t lose weight. There was no control group.

Health Effects:

  • Total Cholesterol went down by 16%.
  • LDL Cholesterol went down by 22%.
  • Triglycerides went down by 35%.
  • Insulin AUC went down by 39%.
  • Diastolic Blood Pressure went down by 3.4 mmHg.

5. Ryberg, et al. A Palaeolithic-type diet causes strong tissue-specific effects on ectopic fat deposition in obese postmenopausal women. Journal of Internal Medicine, 2013.

Details: 10 healthy women with a BMI over 27 consumed a modified paleolithic diet for 5 weeks. There was no control group.

Main outcomes measured were liver fat, muscle cell fat and insulin sensitivity.

Weight Loss: The women lost an average of 4.5 kg (9.9 lbs) and had an 8 cm (3.1 inches) reduction in waist circumference.

Liver and Muscle Fat: The fat content of liver and muscle cells are a risk factor for metabolic disease. In this study, the women had an average reduction in liver fat of 49%, but no significant effect on the fat content of muscle cells.

This graph shows how the fat content in liver cells decreased:

As you can see, the women who had a lot of liver fat (fatty liver) had the most significant decrease.

Other Health Effects:

Conclusion: During the 5 week trial, the women lost weight and had major reductions in liver fat. They also had improvements in several important health markers.

The Results are in: 28-Day Transformation Challenge Recap

At the beginning of January, I started a 28-Day Transformation Challenge that has truly been a life-changing experience for me. The challenge consisted of 3 key commitments I pledged to make from January 7 through February 3, 2013:

  1. Eat a paleo diet (no grains/gluten, no beans, no sugar, no alcohol, no preservatives).
  2. Exercise for at least 10 minutes a day.
  3. Take fish oil supplements (minimum 2,000 mg) daily.

My goal for the challenge was to achieve a perfect score. Not because I was trying to lose weight. Not because I wanted to win (ok, ok, I wanted to win). But to see what I was capable of. To remain completely committed to and disciplined about something that I knew would be hard for me. Really, really hard for me.

I’m proud to report that I achieved a perfect score. I never deviated from the paleo diet food plan. I took my fish oils religiously. And I exercised for at least 10 minutes every day (a heck of a lot more than that on most days). During the challenge, I ate a plate of broccoli at a friend’s house while everyone else chowed down on lasagna and bread *gasp!* I drank water and ate carrots dipped in guacamole during a NFL playoff game while everyone else had beer and chips. I did what I said I was going to do. And for that, I am proud. For that, I am stronger.

Before the challenge, I can safely say I was addicted to and dependent on sugar and bread. I never went a day without eating a sandwich at lunch or a side of grains with dinner. And I always had a “healthy” sweet treat for dessert. Thinking about embarking on 28 days with very few of the things I was accustomed to eating every day scared me. I thought it was going to be incredibly hard. I remember scoffing at the idea of giving up whole food groups in the past. However, I quickly found myself looking at my perception of what is and isn’t healthy very differently.

So did it pay off? Yes. I didn’t lose any weight, but that wasn’t the goal. Here were some results that amazed me:

  • I reduced my body fat percentage by 1.2%, dropping from 19.4% to 18.2%.
  • I lost an inch at my waist and more than an inch at my chest.
  • I have seen some positive changes in my body definition, particularly in my arms and abs.
  • We did 100 burpees for time before and after the challenge. I improved my time by 10.5%, reducing my time from 8 minutes and 2 seconds to 7 minutes and 16 seconds.
  • I had more energy. I was not as tired during the day as I’d been feeling prior to the challenge, and even after tiring days I was still wide awake (and I don’t drink caffeine).
  • I’ve noticed that my speed work and long runs have been stronger and faster. I’m also seeing positive results during my strength training sessions as well.
  • I discovered some amazing new recipes that I love and now cook often. You can check them out on my clean eating paleo pinterest board here.

Going into the challenge, I expected to feel crazy. To feel completely deprived and yearning for grains and sugar. Instead, I found myself feeling the opposite. Instead of feeling crazy, for the first time I felt completely in control of my food choices and practiced some insane will power. Doing this together with Mr. rUnladylike was also a nice chance for us to have something to focus on and do together, often tag teaming on dinner and motivating one another on the days where all we wanted was some Mellow Mushroom pizza.

In terms of overall challenges, I think I encountered 3 big issues:

  1. Being in social settings was hard. Going out to dinner and finding something that fits within the parameters of the challenge and paleo diet is very difficult. Everything seems to be cooked in butter or canola oil, and there are often so many added ingredients or preservatives in everything. Going to parties at friends’ houses was even more challenging, because I had the extra layer of guilt that I couldn’t eat much of what they cooked. Mr. rUnladylike and I found ourselves avoiding social events during the challenge because it just made things harder. And that isn’t a realistic way to live.
  2. Adjusting to the paleo diet takes a lot more of your time. Extra time and planning are critical to making this diet a success. Cooking chicken breasts, boiling eggs, cutting up lettuce and more on Sundays for the week and spending extra time cooking breakfast rather than grabbing a cup of Greek yogurt on the way out the door was definitely an adjustment.
  3. I found myself binging on dried fruit to overcompensate on some of the snacks and foods I missed. I ate way too many raisins during the challenge. Way. Too. Many. I also discovered medjool dates and started a love affair with them. I may have possibly eaten my body weight in those delicious morsels. I must exercise more will power when it comes to that moving forward.

Will I keep following the paleo diet now that the 28-Day Transformation Challenge is over?
Yes, I will. However, I will allow myself some cheat days. I figure if 90 percent of the time I follow the paleo diet and 10 percent of the time I let real life in – dinner parties at friends’ houses, enjoying a meal at a favorite restaurant, a dessert to celebrate something special – then I think I’ll be doing pretty well. I will also build Honey Stinger Gels back into my training regimen to use as fuel during long runs (I used raisins during the challenge), as well as Nuun tablets to aid hydration and electrolyte replacement.

I am looking at food in a completely different way than I did at the beginning of the year. Sometimes I feel like I have a secret that so many people around me haven’t figured out yet. It’s such an interesting and empowering feeling to know I am eating real food. That I am not letting fake, processed, addictive ingredients get the better of me (ok, most of the time). That is change in action.

Have you ever tried the paleo diet? What did you enjoy the most? What were your greatest challenges? If you made a New Year’s resolution this year, are you still sticking to it or have you fallen off the wagon? How will you stay motivated to keep your health commitments you made in January?

It’s been a rough year for adherents of the Paleo diet, the meat-forward lifestyle that took Robert Atkins’s ideas back 10,000 years to declare war on carbs.

First, the Paleo Guy himself, New Zealand nutritionist Jamie Scott is separating himself from what he thinks the movement has become. More recently, a study found that people lost more fat on a low-fat diet than on a low-carb one. And the latest blow: the University Chicago’s Quarterly Review of Biology has released a report that calls into question one of the cornerstone beliefs of Paleo carnivores: that it was a switch to meat in the hominid diet, brought about by the advent of hunting equipment during the stone age, that led to the increased brain size that distinguishes humans from our heavier-browed forefathers.

But according to evolutionary biologist Karen Hardy and her colleagues, carbohydrates played an essential role in the developing of bigger brains. A high-functioning human brain needs lots of glucose, which carbs provide.

In a perfect world, this might lead people to chill out some on the strictures of the Paleo diet, or at least the way they talk about it. But our world is far from perfect, and it’s unlikely that people will stop being as insufferable as they (we) are. So in an attempt to help even just a little bit in this regard, I’ll cite some of the leaders of the Paleo movement, and point out the errors in their thinking.

The anti-potato crusader

Self-proclaimed “world’s leading expert on paleolithic diets” Colorado State professor Dr Loren Cordain is widely acknowledged as the founder of the Paleo movement, and probably the most vociferous anti-potato crusader on the planet. (The paleo community is generally more forgiving of sweet potatoes and yams, which are seen as a “healthier” option.)

“I have noticed in the last few years that many Paleo dieters believe that potatoes can be regularly consumed without any adverse health effects,” he says. “Part of this misinformation seems to stem from writers of blogs and others who are unfamiliar with the scientific literature regarding potatoes.”

But according to Hardy’s findings, eating starchy tubers like potatoes is precisely what allowed our hunting-gathering ancestors to thrive. “The regular consumption of starchy plant foods offers a coherent explanation for the provision of energy to the developing brain during the Late Pliocene and Early Pleistocene,” she says.

“While the development of cooking, and a concomitant increase in salivary amylase expression, explains how the rapid increases in brain size from the Middle Pleistocene onward were energetically affordable.”

The ‘primal enthusiast’

Founder of Primal Blueprint Publishing and author of the popular blog Mark’s Daily Apple, former Ironman World Championship competitor Mark Sisson recommends a daily intake of 100 to 150 grams of carbs, and calls the 150-300 gram recommendation of the USDA “irresponsible” (by the way, you can become a “certified” primal blueprint expert for “only $1 down”, according to an add at Sisson’s website, which is surely a far more responsible thing to do).

Hardy offers “a more realistic recommendation for the practical minimal requirement of 150g/day of glycemic carbohydrate intake beyond the ages of three to four years”.

The metabolic medicine expert

An “internationally known expert in nutritional and metabolic medicine whose work with diabetics is truly groundbreaking”, according to his own website, Dr Ron Rosedale is listed as one of the “top 17 low-carb & paleo doctors with blogs” on the “authority nutrition” site that comes up on the first page of a Google search for “paleo doctor”.

Rosedale says, “Don’t worry about getting enough carbohydrates. They are everywhere, so avoiding them completely is impossible. That said, you don’t NEED any at all. Contrary to popular belief, there is no lower limit to the amount of sugar your body needs.”

Hardy, for her part, says, “modern humans require a reliable source of glycemic carbohydrate to support the normal functioning of our brain, kidney medulla, red blood cells and reproductive tissues. The brain alone accounts for 20–25% of adult basal metabolic expenditure. In addition to the demands of the brain, red blood cells require approximately 20g glucose per day directly from the bloodstream. Under normal circumstances, a glucose requirement of approximately 170g/day is met …”

Enough, right?

Surely, some of the ideas that inform Paleo thinking have some value (I for one could probably stand to cut back on the potato chips). But the same can be said for most belief systems – and any strict lifestyle regimen that claims to have “cracked the code” and discovered the one true path to healthier existence is bound to be bullshit.

Come on, man. Come on, Early Man.

• This article was amended on 19 August 2015. The recent study cited in Time Magazine found that people lost more fat, not more weight, on a low-fat diet than people did on a low-carb diet. This article was further amended on 21 August 2015 to clarify a reference to Jamie Scott.

Meet Grok. According to his online profile, he is a tall, lean, ripped and agile 30-year-old. By every measure, Grok is in superb health: low blood pressure; no inflammation; ideal levels of insulin, glucose, cholesterol and triglycerides. He and his family eat really healthy, too. They gather wild seeds, grasses, and nuts; seasonal vegetables; roots and berries. They hunt and fish their own meat. Between foraging, building sturdy shelters from natural materials, collecting firewood and fending off dangerous predators far larger than himself, Grok’s life is strenuous, perilous and physically demanding. Yet, somehow, he is a stress-free dude who always manages to get enough sleep and finds the time to enjoy moments of tranquility beside gurgling creeks. He is perfectly suited to his environment in every way. He is totally Zen.

Ostensibly, Grok is “a rather typical hunter–gatherer” living before the dawn of agriculture—an “official primal prototype.” He is the poster-persona for fitness author and blogger Mark Sisson’s “Primal Blueprint”—a set of guidelines that “allows you to control how your genes express themselves in order to build the strongest, leanest, healthiest body possible, taking clues from evolutionary biology (that’s the primal part).” These guidelines incorporate many principles of what is more commonly known as the Paleolithic, or caveman, diet, which started to whet people’s appetites as early as the 1960s and is available in many different flavors today.

Proponents of the Paleo diet follow a nutritional plan based on the eating habits of our ancestors in the Paleolithic period, between 2.5 million and 10,000 years ago. Before agriculture and industry, humans presumably lived as hunter–gatherers: picking berry after berry off of bushes; digging up tumescent tubers; chasing mammals to the point of exhaustion; scavenging meat, fat and organs from animals that larger predators had killed; and eventually learning to fish with lines and hooks and hunt with spears, nets, bows and arrows.

Most Paleo dieters of today do none of this, with the exception of occasional hunting trips or a little urban foraging. Instead, their diet is largely defined by what they do not do: most do not eat dairy or processed grains of any kind, because humans did not invent such foods until after the Paleolithic; peanuts, lentils, beans, peas and other legumes are off the menu, but nuts are okay; meat is consumed in large quantities, often cooked in animal fat of some kind; Paleo dieters sometimes eat fruit and often devour vegetables; and processed sugars are prohibited, but a little honey now and then is fine.

Almost equal numbers of advocates and critics seem to have gathered at the Paleo diet dinner table and both tribes have a few particularly vociferous members. Critiques of the Paleo diet range from the mild—Eh, it’s certainly not the worst way to eat—to the acerbic: It is nonsensical and sometimes dangerously restrictive. Most recently, in her book Paleofantasy, evolutionary biologist Marlene Zuk of the University of California, Riverside, debunks what she identifies as myths central to the Paleo diet and the larger Paleo lifestyle movement.

Most nutritionists consent that the Paleo diet gets at least one thing right—cutting down on processed foods that have been highly modified from their raw state through various methods of preservation. Examples include white bread and other refined flour products, artificial cheese, certain cold cuts and packaged meats, potato chips, and sugary cereals. Such processed foods often offer less protein, fiber and iron than their unprocessed equivalents, and some are packed with sodium and preservatives that may increase the risk of heart disease and certain cancers.

But the Paleo diet bans more than just highly processed junk foods—in its most traditional form, it prohibits any kind of food unavailable to stone age hunter–gatherers, including dairy rich in calcium, grains replete with fiber, and vitamins and legumes packed with protein. The rationale for such constraint—in fact the entire premise of the Paleo diet—is, at best, only half correct. Because the human body adapted to life in the stone age, Paleo dieters argue—and because our genetics and anatomy have changed very little since then, they say—we should emulate the diets of our Paleo predecessors as closely as possible in order to be healthy. Obesity, heart disease, diabetes, cancer and many other “modern” diseases, the reasoning goes, result primarily from the incompatibility of our stone age anatomy with our contemporary way of eating.

Diet has been an important part of our evolution—as it is for every species—and we have inherited many adaptations from our Paleo predecessors. Understanding how we evolved could, in principle, help us make smarter dietary choices today. But the logic behind the Paleo diet fails in several ways: by making apotheosis of one particular slice of our evolutionary history; by insisting that we are biologically identical to stone age humans; and by denying the benefits of some of our more modern methods of eating.

“‘Paleofantasies’ call to mind a time when everything about us—body, mind, and behavior—was in sync with the environment…but no such time existed,” Zuk wrote in her book. “We and every other living thing have always lurched along in evolutionary time, with the inevitable trade-offs that are a hallmark of life.”

On his website, Sisson writes that “while the world has changed in innumerable ways in the last 10,000 years (for better and worse), the human genome has changed very little and thus only thrives under similar conditions.” This is simply not true. In fact, this reasoning misconstrues how evolution works. If humans and other organisms could only thrive in circumstances similar to the ones their predecessors lived in, life would not have lasted very long.

Several examples of recent and relatively speedy human evolution underscore that our anatomy and genetics have not been set in stone since the stone age. Within a span of 7,000 years, for instance, people adapted to eating dairy by developing lactose tolerance. Usually, the gene encoding an enzyme named lactase—which breaks down lactose sugars in milk—shuts down after infancy; when dairy became prevalent, many people evolved a mutation that kept the gene turned on throughout life. Likewise, the genetic mutation responsible for blue eyes likely arose between 6,000 and 10,000 years ago. And in regions where malaria is common, natural selection has modified people’s immune systems and red blood cells in ways that help them resist the mosquito-borne disease; some of these genetic mutations appeared within the last 10,000 or even 5,000 years. The organisms with which we share our bodies have evolved even faster, particularly the billions of bacteria living in our intestines. Our gut bacteria interact with our food in many ways, helping us break down tough plant fibers, but also competing for calories. We do not have direct evidence of which bacterial species thrived in Paleolithic intestines, but we can be sure that their microbial communities do not exactly match our own.

Even if eating only foods available to hunter–gatherers in the Paleolithic made sense, it would be impossible. As Christina Warinner of the University of Zurich emphasizes in her 2012 TED talk, just about every single species commonly consumed today—whether a fruit, vegetable or animal—is drastically different from its Paleolithic predecessor. In most cases, we have transformed the species we eat through artificial selection: we have bred cows, chickens and goats to provide as much meat, milk and eggs as possible and have sown seeds only from plants with the most desirable traits—with the biggest fruits, plumpest kernels, sweetest flesh and fewest natural toxins. Cabbage, broccoli, cauliflower, Brussels sprouts and kale are all different cultivars of a single species, Brassica oleracea; generation by generation, we reshaped this one plant’s leaves, stems and flowers into wildly different arrangements, the same way we bred Welsh corgis, pugs, dachshunds, Saint Bernards and greyhounds out of a single wolf species. Corn was once a straggly grass known as teosinte and tomatoes were once much smaller berries. And the wild ancestors of bananas were rife with seeds.

The Paleo diet not only misunderstands how our own species, the organisms inside our bodies and the animals and plants we eat have evolved over the last 10,000 years, it also ignores much of the evidence about our ancestors’ health during their—often brief—individual life spans (even if a minority of our Paleo ancestors made it into their 40s or beyond, many children likely died before age 15). In contrast to Grok, neither Paleo hunter–gatherers nor our more recent predecessors were sculpted Adonises immune to all disease. A recent study in The Lancet looked for signs of atherosclerosis—arteries clogged with cholesterol and fats—in more than one hundred ancient mummies from societies of farmers, foragers and hunter–gatherers around the world, including Egypt, Peru, the southwestern U.S and the Aleutian Islands. “A common assumption is that atherosclerosis is predominately lifestyle-related, and that if modern human beings could emulate preindustrial or even preagricultural lifestyles, that atherosclerosis, or least its clinical manifestations, would be avoided,” the researchers wrote. But they found evidence of probable or definite atherosclerosis in 47 of 137 mummies from each of the different geographical regions. And even if heart disease, cancer, obesity and diabetes were not as common among our predecessors, they still faced numerous threats to their health that modern sanitation and medicine have rendered negligible for people in industrialized nations, such as infestations of parasites and certain lethal bacterial and viral infections.

Some Paleo dieters emphasize that they never believed in one true caveman lifestyle or diet and that—in the fashion of Sisson’s Blueprint—they use our evolutionary past to form guidelines, not scripture. That strategy seems reasonably solid at first, but quickly disintegrates. Even though researchers know enough to make some generalizations about human diets in the Paleolithic with reasonable certainty, the details remain murky. Exactly what proportions of meat and vegetables did different hominid species eat in the Paleolithic? It’s not clear. Just how far back were our ancestors eating grains and dairy? Perhaps far earlier than we initially thought. What we can say for certain is that in the Paleolithic, the human diet varied immensely by geography, season and opportunity. “We now know that humans have evolved not to subsist on a single, Paleolithic diet but to be flexible eaters, an insight that has important implications for the current debate over what people today should eat in order to be healthy,” anthropologist William Leonard of Northwestern University wrote in Scientific American in 2002.

Jen Christiansen

We cannot time travel and join our Paleo ancestors by the campfire as they prepare to eat; likewise, shards of ancient pottery and fossilized teeth can tell us only so much. If we compare the diets of so-called modern hunter-gatherers, however, we see just how difficult it is to find meaningful commonalities and extract useful dietary guidelines from their disparate lives (see infographic). Which hunter–gatherer tribe are we supposed to mimic, exactly? How do we reconcile the Inuit diet—mostly the flesh of sea mammals—with the more varied plant and land animal diet of the Hadza or !Kung? Chucking the many different hunter–gather diets into a blender to come up with some kind of quintessential smoothie is a little ridiculous. “Too often modern health problems are portrayed as the result of eating ‘bad’ foods that are departures from the natural human diet…This is a fundamentally flawed approach to assessing human nutritional needs,” Leonard wrote. “Our species was not designed to subsist on a single, optimal diet. What is remarkable about human beings is the extraordinary variety of what we eat. We have been able to thrive in almost every ecosystem on the Earth, consuming diets ranging from almost all animal foods among populations of the Arctic to primarily tubers and cereal grains among populations in the high Andes.”

Closely examining one group of modern hunter–gatherers—the Hiwi—reveals how much variation exists within the diet of a single small foraging society and deflates the notion that hunter–gatherers have impeccable health. Such examination also makes obvious the immense gap between a genuine community of foragers and Paleo dieters living in modern cities, selectively shopping at farmers’ markets and making sure the dressing on their house salad is gluten, sugar and dairy free.

Illustration by Marissa Fessenden

By latest count, about 800 Hiwi live in palm thatched huts in Colombia and Venezuela. In 1990 Ana Magdalena Hurtado and Kim Hill—now both at Arizona State University in Tempe—published a thorough study (pdf) of the Hiwi diet in the neotropical savannas of the Orinoco River basin in Southwestern Venezuela. Vast grasslands with belts of forest, these savannas receive plenty of rain between May and November. From January through March, however, precipitation is rare: the grasses shrivel, while lakes and lagoons evaporate. Fish trapped in shrinking pools of water are easy targets for caiman, capybaras and turtles. In turn, the desiccating lakes become prime hunting territory for the Hiwi. During the wet season, however, the Hiwi mainly hunt for animals in the forest, using bows and arrows.

The Hiwi gather and hunt a diverse group of plants and animals from the savannas, forests, rivers and swamps. Their main sources of meat are capybara, collared peccary, deer, anteater, armadillo, and feral cattle, numerous species of fish, and at least some turtle species. Less commonly consumed animals include iguanas and savanna lizards, wild rabbits, and many birds. Not exactly the kind of meat Paleo dieters and others in urban areas can easily obtain.

Five roots, both bitter and sweet, are staples in the Hiwi diet, as are palm nuts and palm hearts, several different fruits, a wild legume named Campsiandra comosa, and honey produced by several bee species and sometimes by wasps. A few Hiwi families tend small, scattered and largely unproductive fields of plantains, corn and squash. At neighboring cattle ranches in a town about 30 kilometers away, some Hiwi buy rice, noodles, corn flour and sugar. Anthropologists and tourists have also given the Hiwi similar processed foods as gifts (see illustration at top).

Hill and Hurtado calculated that foods hunted and collected in the wild account for 95 percent of the Hiwi’s total caloric intake; the remaining 5 percent comes from store-bought goods as well as from fruits and squash gathered from the Hiwi’s small fields. They rely more on purchased goods during the peak of the dry season.

The Hiwi are not particularly healthy. Compared to the Ache, a hunter–gatherer tribe in Paraguay, the Hiwi are shorter, thinner, more lethargic and less well nourished. Hiwi men and women of all ages constantly complain of hunger. Many Hiwi are heavily infected with parasitic hookworms, which burrow into the small intestine and feed on blood. And only 50 percent of Hiwi children survive beyond the age of 15.

Drop Grok into the Hiwi’s midst—or indeed among any modern or ancient hunter–gather society—and he would be a complete aberration. Grok cannot teach us how to live or eat; he never existed. Living off the land or restricting oneself to foods available before agriculture and industry does not guarantee good health. The human body is not simply a collection of adaptations to life in the Paleolithic—its legacy is far greater. Each of us is a dynamic assemblage of inherited traits that have been tweaked, transformed, lost and regained since the beginning of life itself. Such changes have not ceased in the past 10,000 years.

Ultimately—regardless of one’s intentions—the Paleo diet is founded more on privilege than on logic. Hunter–gatherers in the Paleolithic hunted and gathered because they had to. Paleo dieters attempt to eat like hunter–gatherers because they want to.

The Paleo Diet – Healthy or Hoax?

No association could be found between total saturated fats and coronary disease risk.

While the link between saturated fats and cardiovascular disease has been refuted a number of times, those claiming that the saturated fats consumed in the paleo diet continue to preach that those fats will “quickly ratchet up your risk for heart problems” (to quote US News and World Report). Most recently, the Annals of Internal Medicine presented a study done by an international team led by the University of Cambridge’s Dr. Rajiv Chowdhury which collated and reanalyzed data from 72 separate studies involving over 600,000 participants. According to this report, after reviewing these 72 studies, no association could be found between total saturated fats and coronary disease risk.

For those claiming that the paleo lifestyle isn’t maintainable, I would agree that switching to a more primal way of eating certainly requires more time for meal planning and preparation. However, knowing that the average American spends about three hours per day sitting in front of the television, it seems that with proper time management, this paleo thing might be easier than they think. When it comes to the idea that the paleo diet is too time consuming, it takes about the same amount of time to hit the produce and meat sections of the grocery store as it does those processed food-filled inner aisles and grilling up that chicken and vegetable dinner really doesn’t take much longer than to prepare a boxed dinner. As for being more expensive, yes – the foods promoted on a Paleolithic diet tend to be more costly than those processed foods. However, I can assure you the extra money spent on these high quality foods is a solid investment. Wouldn’t you rather spend your money on grass-fed meats and organic vegetables than prescription pills and surgeries?

The bottom line is that times are changing, research is changing, and the health of our nation is changing. We’ve seen the low-fat trend fail, leaving us fatter and sicker than ever. We’ve watched rates of heart disease, cancer, and diabetes climb while autoimmune diseases and obesity become more prevalent by the day. It’s time to begin thinking outside the box, to challenge our prior views on nutrition, and, if nothing else, seriously look at the research and clinical applications around an ancestral diet. While a strict paleo diet may not be for everybody, the fundamentals of this lifestyle are exceptional. I’ve seen this lifestyle work too many times for too many people to even consider that this might not be one of the best diets around today. What else can I say? Results speak louder than reports.

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