This Year the Annual Diet Reviews Didn’t Have Their Usually Sharp Teeth Out for the Paleo Diet
It’s January. Which means another flurry of online diet rankings and reviews. At the Paleo Diet®, we await them with the rapt anticipation of a school boy sweating his double-dare challenge punishment. You don’t know what it’s going to be. You just know it’s going to hurt.
In a strange way, we came to wear our dead last ranking at US News & World Report as a badge of pride. Instead of discouraging paleo dieters, the ranking seemed to make them feel part of an idea that was not appreciated in its time. With a certain combination of self-awareness and a little self-delusion the rankings put paleo dieters on a shelf with figures like Socrates, Giordana Bruno, and Galileo. Just with better foods – hemlock isn’t part of any nutritious breakfast – and a lot less execution.
But this year, something felt different about the rankings.
In 2019, US News swapped our dead last for 33d out of 41 diets and even begrudgingly admitted “the Paleo Diet is relatively convenient these days.” Sure, they still didn’t recommend the diet and used lots of subtle qualifiers like “little” and “difficult,” but the sharp teeth of previous years simply weren’t there.
Another January review of diets on the UK’s largest health website, NHS, admitted some pretty strong positives such as “the diet is simple and doesn’t involved calorie counting.” Their final verdict was still mixed, but it didn’t have the dismissiveness we’re used to.
So why the change?
Honestly, we don’t know. One possibility is the fact that this year, the bulk of US News’ write up included a review of recent Paleo Diet studies. They still couldn’t resist pointing out “small” sample sizes and a study where the Mediterranean diet was comparable, but the fact was, the studies were favorable.
In the past, US News attacked the Paleo Diet based on a misconception that there was “no science behind it.” But now with a rapidly growing body of positive research (see the full list at the bottom of this article) and a recent review rigorously evaluating all of the diets listed in the US News report , the misconceived “no science” argument has simply lost its bite.
Now if We Could Just Address the Other Misconceptions
Ultimately you, as the reader, needs to draw your own conclusions about the Paleo Diet or any diet. Do your own review. Just base it on the science and the actual diet – not misconceptions. Too often we read a criticism and think “that’s a good point… too bad they’re not talking about the Paleo Diet.”
The list of studies – positive and negative – on the website, will give you the science to draw your own conclusions. So, let’s address the misconceptions in the recent reviews that have been used to criticize the Paleo Diet. That way you can draw your conclusions based on the actual diet:
1. Excluding grains and dairy leads to nutrient deficiencies
“Most versions of the paleo diet exclude key food groups, raising the potential for nutritional deficiencies.” This claim in the NHS review is one of the most common critiques of the Paleo Diet. But this claim is based on the misconception that these foods are simply eliminated and not replaced or substituted by Paleo-friendly foods.
Dr Cordain addressed this misconception in an article titled Eliminating Non-Paleo Foods Improves Nutrient Density. The main point of the article was that grains and dairy are two of the most nutrient-poor categories of foods we can eat. So, replacing calories from these foods with calories from nutrient-rich foods like vegetables and fish actually improves the nutrient density of our diets.
To make this point, Dr Cordain used a peer-reviewed Mediterranean Diet meal plan which was already nutrient dense. He replaced the non-Paleo foods with isocaloric Paleo-friendly foods, and the nutrient density of the meal plan improved.
We’ll give the NHS review credit for stating that the nutrient deficiencies can be avoided with “careful substitution,” though we’d argue that a diet based on low-nutrient density grains is the one that needs careful substitutions.
Finally, it’s worth pointing out that two of the critical nutrients that critics claim we lose by eliminating grains and dairy are folic acid and vitamin D. Grains and dairy are not naturally high in either nutrient – they are fortified. Vegetables, which replace grains in the Paleo Diet are naturally high in folate.
2. It’s an all-protein protein/meat-based diet
US News finished their 2019 review by saying “these diets contain more than the government’s recommendation that between 10 to 35 percent of daily calories come from protein.” Likewise, the NHS review claimed that “most versions of the diet encourage eating a lot of meat, which runs counter current health advice.”
The Paleo Diet does not recommend consuming more than 35 percent of our calories from protein. In fact, Dr Loren Cordain addressed this issue in both the original Paleo Diet book, and series of articles pointing out that eating more than about 35 percent of our calories from protein can lead to a fatal condition called rabbit starvation . Hunter-gatherer diets ranged from 19-35 percent which is within the government recommendations [3, 4].
To take this a step further, meat is calorically dense. Meaning a small volume of meat packs in a lot of calories. With a typical western diet, the calories from meat are quickly overshadowed by high-carb processed foods which are calorically even denser. A six-ounce ribeye may pack 36 grams of protein (equal to about 150 kcal,) but it’s quickly dwarfed by that 600-calorie high-carb and -fat dessert or bag of Cheetos eaten after dinner.
The western diet, with its reliance on grains, makes it easy to keep protein around 10 to 15 percent of daily calories. But a Paleo Diet avoids these high-calorie processed foods. So, to keep protein at a healthy ratio, we must balance meat with vegetables and fruit which have a very low caloric density.
In other words, we have to eat a lot of plant food!
By volume, a typical Paleo Diet is less than 10 percent animal protein. Vegetables and fruit represent the bulk of what we eat.
US News started their review by stating “if the caveman didn’t eat it, you shouldn’t either.” This is a subtle, but important misconception. Many critics like to call it a “caveman” diet. That conjures up the image of a brutish man draped in furs who carries a club and eats nothing but meat. His life is short and brutish and not a life we would want to replicate. Notice that the focus is even on “man.” How many old Loony Toons cartoons showed cavemen bashing women over the head and dragging them by their hair. There is nothing positive about “caveman.”
However, it is easier to criticize a diet when it is associated with an inaccurate and negative stereotype. Case in point, in his critique of the Paleo Diet, Bill Nye used the stereotype to great effect, literally dressing an actor as a caveman:
(Figure 1: Taken from Bill Nye Saves the World)
I wrote an article for the Paleo Diet website addressing his critique. As a fan of Bill Nye, I had hoped for some good scientific arguments, but all I saw were inaccuracies and misconceptions. And at the center of all of them was the “caveman” concept.
The truth is that the Paleo Diet is based on hunter-gatherer societies that have existed throughout the world for most of history. Many of them lived in forested regions, in the great plains, and even in igloos. Few carried clubs or lived in caves. The authentic photo below is a much truer image of hunter-gatherers:
(Figure 2: photo of authentic hunter-gatherers)
If we’re going to use a stereotype, I would recommend watching the wonderful 1990 movie Dances with Wolves where Kevin Costner’s character was so enamored by the rich life of Native American hunter-gatherers, he gave up his western identity. In fact, a major portion of the movie focused on the purity of the buffalo hunt and subsequent feast. Their culture was rich with unique foods and dietary habits. One great example is their invention of pemmican which Dr Cordain covered thoroughly in a recent article.
The Paleo Diet is based on hunter-gatherer societies not “cavemen.” Any serious and unbiased review of the diet should not use the term.
4. We are guessing at what our Paleolithic ancestors ate
This is in fact true. We don’t know exactly what ancient hunter-gatherers ate and often our records of even recent hunter-gatherer diets are incomplete [4-7]. That’s not the misconception.
The misconception is that the Paleo Diet tries to perfectly recreate the exact diet of our Paleolithic ancestors [8, 9]. That is impossible for two reasons. First, many of the foods that existed then do not exist now. Second, there was no one diet. Hunter-gatherers living by the equator ate very differently from hunter-gatherers who lived in the plains, who again ate very differently from Inuit populations. If anything, the research on hunter-gatherer diets makes a strong argument for individualized nutrition .
The danger of this misconception is that critics use it to say that we can’t perfectly replicate paleolithic diets, so the Paleo Diet is a sham.
The truth is that the Paleo Diet uses ethnographic data to create a template for better human nutrition. Put another way, we know that the current Western Diet is unhealthy and leads to the diseases of civilization. So, what is better: starting with a diet that we know is unhealthy, or starting with a diet that is analogous to the diet we evolved around?
And while we don’t know exactly what our paleolithic ancestors ate, we do know what they didn’t eat – grain products, refined sugar, processed foods, vegetable oils, and dairy.
The Biggest Misconception That’s Lost Its Bite: It is Not Based on Science
This is the misconception that has given critics of the Paleo Diet their sharpest teeth and motivated US News to rank the Paleo Diet dead last for years.
It is also the argument that critics can no longer rely on.
For years, critics claimed that there were no peer-reviewed studies or meta-analyses demonstrating the efficacy of the Paleo Diet. At one time, this was in fact true. But the conclusion they then drew – that the diet wasn’t based on science – was a step too far that required a misconception of the scientific process itself.
As it was explained to me in grade school, the scientific process starts with a scientist or group of scientists reviewing the existing research on a subject. Next, these scientists develop a novel theory based on that research. Finally, studies are conducted to test the theory.
What’s important is that every theory (even the most groundbreaking) had a point where they were pure theory without any research to back them up. That does not mean there was no science behind them.
Take the example of one of the greatest scientists – Albert Einstein. Einstein essentially never conducted a research study in his life. His theories of special relativity (1905) and general relativity (1916) were based mostly on thought experiments and past research. Yet, within a few years, these theories had revolutionized Physics, despite the fact that the first experiment to validate special relativity – a fascinating study by Sir Arthur Eddington showing the bending of light – wasn’t conducted until 1919. Fourteen years later. But if that feels long, look at the theory of general relativity which was contingent upon the existence of gravitational waves. Their existence wasn’t proved until 2016 – exactly 100 years later. Yet no one ever claimed that relativity was “based on no science.”
The Paleo Diet is also a theory. It was the result of decades spent by researchers like Loren Cordain, Ph.D., Boyd Eaton, Ph.D., and Staffan Lindeberg, Ph.D. studying the existing science in the fields of nutrition, anthropology and evolutionary biology.
Just like all science – even relativity – paleolithic nutrition had a point where it was a theory and no studies had been conducted to validate it. But it was a misconception for critics to claim it was not based on science. It was based on decades of science. Its only crime was being at the theory stage of the scientific process.
Fortunately, that has changed. Since US News leveled their first review claiming “no science” over 40 studies have been conducted. And most of them have demonstrated favorable results in terms of weight loss, inflammation, and health.
Ironically, the lack of a proper scientific process in US News rankings may have motivated a 2017 review in Nutrients which applied a true systematic review process to the 38 diets in the US News rankings at the time. The review looked only at diets that didn’t require calorie restrictions or supplements which reduced the list to 20 diets.
Of those 20, only seven had high-quality scientific clinical trials evaluating their effectiveness in terms of weight loss. Those diets were the Atkins, DASH, Glycemic-Index, Mediterranean, Ornish, Zone, and of course the Paleo Diet. The review identified two clinical trials that demonstrated both short-term and long-term weight loss on the Paleo Diet. The authors stated “the findings of this review are not in line with current recommendations of the Dietary Guidelines Advisory Committee which state that diets with less than 45% of calories as carbohydrates are not more successful than other diets for long-term weight loss (12 months.) 
It can’t be over-emphasized that while, US News and World Report ranked the Paleo Diet at the bottom of the list based on the “lack of science,” a proper scientific review of all 38 diets, placed the Paleo Diet among the seven with actual scientific backing.
It’s no wonder the US News review is starting to lose its bite.
Current Paleo Diet Studies Up to 2019
- Lindeberg, S., et al., A Palaeolithic diet improves glucose tolerance more than a Mediterranean-like diet in individuals with ischaemic heart disease. Diabetologia, 2007. 50(9): p. 1795-1807.
- Osterdahl, M., et al., Effects of a short-term intervention with a paleolithic diet in healthy volunteers. Eur J Clin Nutr, 2008. 62(5): p. 682-5.
- Frassetto, L.A., et al., Metabolic and physiologic improvements from consuming a paleolithic, hunter-gatherer type diet. Eur J Clin Nutr, 2009. 63(8): p. 947-55.
- Jonsson, T., et al., Beneficial effects of a Paleolithic diet on cardiovascular risk factors in type 2 diabetes: a randomized cross-over pilot study. Cardiovasc Diabetol, 2009. 8: p. 35.
- Klonoff, D.C., The beneficial effects of a Paleolithic diet on type 2 diabetes and other risk factors for cardiovascular disease. J Diabetes Sci Technol, 2009. 3(6): p. 1229-32.
- Jonsson, T., et al., A paleolithic diet is more satiating per calorie than a mediterranean-like diet in individuals with ischemic heart disease. Nutr Metab (Lond), 2010. 7: p. 85.
- Clemens, Z., et al., Childhood absence epilepsy successfully treated with the paleolithic ketogenic diet. Neurol Ther, 2013. 2(1-2): p. 71-6.
- Jonsson, T., et al., Subjective satiety and other experiences of a Paleolithic diet compared to a diabetes diet in patients with type 2 diabetes. Nutr J, 2013. 12: p. 105.
- Ryberg, M., et al., A Palaeolithic-type diet causes strong tissue-specific effects on ectopic fat deposition in obese postmenopausal women. J Intern Med, 2013. 274(1): p. 67-76.
- Boers, I., et al., Favourable effects of consuming a Palaeolithic-type diet on characteristics of the metabolic syndrome: a randomized controlled pilot-study. Lipids Health Dis, 2014. 13: p. 160.
- Carter, P., et al., A Mediterranean diet improves HbA1c but not fasting blood glucose compared to alternative dietary strategies: a network meta-analysis. J Hum Nutr Diet, 2014. 27(3): p. 280-97.
- Mellberg, C., et al., Long-term effects of a Palaeolithic-type diet in obese postmenopausal women: a 2-year randomized trial. Eur J Clin Nutr, 2014. 68(3): p. 350-7.
- Talreja, D., et al., Impact of a Paleolithic Diet on Modifiable Cardiovascular Risk Factors. Journal of Clinical Lipidology, 2014. 8(3): p. 341.
- Tóth, C. and Z. Clemens, Type 1 diabetes mellitus successfully managed with the paleolithic ketogenic diet. Vol. 5. 2014.
- Whalen, K.A., et al., Paleolithic and Mediterranean diet pattern scores and risk of incident, sporadic colorectal adenomas. Am J Epidemiol, 2014. 180(11): p. 1088-97.
- Bligh, H.F., et al., Plant-rich mixed meals based on Palaeolithic diet principles have a dramatic impact on incretin, peptide YY and satiety response, but show little effect on glucose and insulin homeostasis: an acute-effects randomised study. Br J Nutr, 2015. 113(4): p. 574-84.
- Frassetto, L.A., et al., Metabolic and physiologic improvements from consuming a paleolithic, hunter-gatherer type diet. Eur J Clin Nutr, 2015. 69(12): p. 1376.
- Manheimer, E.W., et al., Paleolithic nutrition for metabolic syndrome: systematic review and meta-analysis. Am J Clin Nutr, 2015. 102(4): p. 922-32.
- Masharani, U., et al., Metabolic and physiologic effects from consuming a hunter-gatherer (Paleolithic)-type diet in type 2 diabetes. Eur J Clin Nutr, 2015. 69(8): p. 944-8.
- Pastore, R.L., J.T. Brooks, and J.W. Carbone, Paleolithic nutrition improves plasma lipid concentrations of hypercholesterolemic adults to a greater extent than traditional heart-healthy dietary recommendations. Nutr Res, 2015. 35(6): p. 474-9.
- Stomby, A., et al., Diet-induced weight loss has chronic tissue-specific effects on glucocorticoid metabolism in overweight postmenopausal women. Int J Obes (Lond), 2015. 39(5): p. 814-9.
- Talreja, A., et al., CRT-601 The VA Beach Diet Study: An Investigation Of The Effects Of Plant-based, Mediterranean, Paleolithic, And Dash Diets On Cardiovascular Disease Risk. 2015. 8(2 Supplement): p. S41.
- Dolan C, C.A., Davies N, Markofski M. , Effects of an 8-week Paleo dietary intervention on inflammatory cytokines, in American Physiological Society Conference, Inflammation, Immunity and Cardiovascular Disease. 2016: Westminster, CO. p. pp 40-41.
- Fontes-Villalba, M., et al., Palaeolithic diet decreases fasting plasma leptin concentrations more than a diabetes diet in patients with type 2 diabetes: a randomised cross-over trial. Cardiovasc Diabetol, 2016. 15: p. 80.
- Talreja, D., et al., CRT-800.00 An Investigation of Plant-based, Mediterranean, Paleolithic, and Dash Diets. 2016. 9(4 Supplement): p. S61.
- Whalen, K.A., et al., Paleolithic and Mediterranean Diet Pattern Scores Are Inversely Associated with Biomarkers of Inflammation and Oxidative Balance in Adults. J Nutr, 2016. 146(6): p. 1217-26.
- Afifi, L., et al., Dietary Behaviors in Psoriasis: Patient-Reported Outcomes from a U.S. National Survey. Dermatol Ther (Heidelb), 2017. 7(2): p. 227-242.
- Anton, S.D., et al., Effects of Popular Diets without Specific Calorie Targets on Weight Loss Outcomes: Systematic Review of Findings from Clinical Trials. Nutrients, 2017. 9(8).
- Blomquist, C., et al., Attenuated Low-Grade Inflammation Following Long-Term Dietary Intervention in Postmenopausal Women with Obesity. Obesity (Silver Spring), 2017. 25(5): p. 892-900.
- Haskey, N. and D.L. Gibson, An Examination of Diet for the Maintenance of Remission in Inflammatory Bowel Disease. Nutrients, 2017. 9(3): p. 259.
- Irish, A.K., et al., Randomized control trial evaluation of a modified Paleolithic dietary intervention in the treatment of relapsing-remitting multiple sclerosis: a pilot study. Degener Neurol Neuromuscul Dis, 2017. 7: p. 1-18.
- Lee, J.E., et al., A Multimodal, Nonpharmacologic Intervention Improves Mood and Cognitive Function in People with Multiple Sclerosis. J Am Coll Nutr, 2017. 36(3): p. 150-168.
- Obert, J., et al., Popular Weight Loss Strategies: a Review of Four Weight Loss Techniques. Curr Gastroenterol Rep, 2017. 19(12): p. 61.
- Otten, J., et al., Benefits of a Paleolithic diet with and without supervised exercise on fat mass, insulin sensitivity, and glycemic control: a randomized controlled trial in individuals with type 2 diabetes. Diabetes Metab Res Rev, 2017. 33(1).
- Stomby, A., et al., A Paleolithic Diet with and without Combined Aerobic and Resistance Exercise Increases Functional Brain Responses and Hippocampal Volume in Subjects with Type 2 Diabetes. Front Aging Neurosci, 2017. 9: p. 391.
- Blomquist, C., et al., Decreased lipogenesis-promoting factors in adipose tissue in postmenopausal women with overweight on a Paleolithic-type diet. Eur J Nutr, 2018. 57(8): p. 2877-2886.
- Cheng, E., et al., Associations of evolutionary-concordance diet, Mediterranean diet and evolutionary-concordance lifestyle pattern scores with all-cause and cause-specific mortality. Br J Nutr, 2018: p. 1-10.
- Genoni, A., et al., A Paleolithic diet lowers resistant starch intake but does not affect serum trimethylamine-N-oxide concentrations in healthy women. Br J Nutr, 2018: p. 1-14.
- Haridass, V., et al., Diet Quality Scores Inversely Associated with Postmenopausal Breast Cancer Risk Are Not Associated with Premenopausal Breast Cancer Risk in the California Teachers Study. J Nutr, 2018. 148(11): p. 1830-1837.
- Manousou, S., et al., A Paleolithic-type diet results in iodine deficiency: a 2-year randomized trial in postmenopausal obese women. Eur J Clin Nutr, 2018. 72(1): p. 124-129.
- Otten, J., et al., A heterogeneous response of liver and skeletal muscle fat to the combination of a Paleolithic diet and exercise in obese individuals with type 2 diabetes: a randomised controlled trial. Diabetologia, 2018. 61(7): p. 1548-1559.
- Popp, C.J., et al., The Effectiveness of MyPlate and Paleolithic-based Diet Recommendations, both with and without Exercise, on Aerobic Fitness, Muscular Strength and Anaerobic Power in Young Women: A Randomized Clinical Trial. Int J Exerc Sci, 2018. 11(2): p. 921-933.
- van Niekerk, G., et al., Nutrient excess and autophagic deficiency: explaining metabolic diseases in obesity. Metabolism, 2018. 82: p. 14-21.
- Wahls, T., et al., Dietary approaches to treat MS-related fatigue: comparing the modified Paleolithic (Wahls Elimination) and low saturated fat (Swank) diets on perceived fatigue in persons with relapsing-remitting multiple sclerosis: study protocol for a randomized controlled trial. Trials, 2018. 19(1): p. 309.
- Anton, S.D., et al., Effects of Popular Diets without Specific Calorie Targets on Weight Loss Outcomes: Systematic Review of Findings from Clinical Trials. Nutrients, 2017. 9(8).
- Cordain, L., The Paleo diet : lose weight and get healthy by eating the food you were designed to eat. 2002, New York: J. Wiley. ix, 257 p.
- Cordain, L., et al., Origins and evolution of the Western diet: health implications for the 21st century. Am J Clin Nutr, 2005. 81(2): p. 341-54.
- Cordain, L., et al., Plant-animal subsistence ratios and macronutrient energy estimations in worldwide hunter-gatherer diets. Am J Clin Nutr, 2000. 71(3): p. 682-92.
- Cordain, L., et al., Macronutrient estimations in hunter-gatherer diets. Am J Clin Nutr, 2000. 72(6): p. 1589-92.
- Eaton, S.B. and M. Konner, Paleolithic nutrition. A consideration of its nature and current implications. N Engl J Med, 1985. 312(5): p. 283-9.
- Cordain, L., J. Miller, and N. Mann, Scant evidence of periodic starvation among hunter-gatherers. Diabetologia, 1999. 42(3): p. 383-4.
- Cordain, L., The nutritional characteristics of a contemporary diet based upon Paleolithic food groups. Journal of the American Nutraceutical Association, 2002. 5(5): p. 15-24.
- Cordain, L., The Paleo diet : lose weight and get healthy by eating the foods you were designed to eat. Rev. ed. 2011, Hoboken, N.J.: Wiley. xv, 266 p.