Paleo diet

A paleo diet is one based on the premise that the optimal diet is that of our evolutionary ancestors during the paleolithic era when the estimated life expectancy was 33 years.Three Stages of Health Encounters Over 8000 Human Generations and How They Inform Future Public Health by Lee Goldman (2018) Am. J. Public Health 108(1): 60–62. doi:10.2105/AJPH.2017.304164. It is essentially an appeal to ancient wisdom fallacy. Since many diets fit this heuristic, many variants have been developed and popularised under names such as caveman diet, paleolithic diet, and primal diet. It is a fad diet. Actual paleolithic-era diets were pre-agricultural, hence food was obtained from hunting and gathering. A paleo diet is typically based on eating only those foods that the adherent believes a hunter-gatherer society would have eaten, such as meat, nuts, berries, fish, vegetables, fruits, and tubers. Typically excluded are foods that are the products of large-scale agriculture such as grains, bread, dairy products (in some versions), legumes (beans, peas), and processed sugar and salt. The Paleolithic era in Europe lasted until roughly 12,000 BCE.
What paleo advocates call the paleolithic diet and what paleolithic diets actually were do not necessarily line up. For example, based on initial chemical studies of human bones from the Paleolithic era, it was shown that humans did eat a lot of animal protein. It was initially difficult to ascertain what else humans might have eaten then because plant material did not preserve well at such archaeological sites. A recent study of Balkan hunter-gatherers found that they gathered, processed, and ate wild starchy grains at least as early as around 11,500 BCE. A taste for wild cereal sowed farming’s spread in ancient Europe: Balkan hunter-gatherers ate starchy grains several millennia before they cultivated crops by Bruce Bower (February 1, 2022 at 7:00 am) Science News.Wild cereal grain consumption among Early Holocene foragers of the Balkans predates the arrival of agriculture by Emanuela Cristiani et al. (Dec 1, 2021) eLife. doi:10.7554/eLife.72976.
The "paleo diet", like most diets, has evolved over time and has many variants. Its earliest phase is associated with and is based around only paleo food-types, as above.Published Research The Paleo Diet (archived from August 23, 2012). It is the diet in this guise that has attracted the most research in terms of diet trials.Metabolic and physiologic improvements from consuming a paleolithic, hunter-gatherer type diet by L. A. Frassetto et al. ((2009) Eur. J. Clin. Nutr. 63(8):947-55. doi:10.1038/ejcn.2009.4.Effects of a short-term intervention with a paleolithic diet in healthy volunteers by M. Österdahl et al. (2008) European Journal of Clinical Nutrition 62:682–685. doi:10.1038/sj.ejcn.1602790A Palaeolithic diet improves glucose tolerance more than a Mediterranean-like diet in individuals with ischaemic heart disease. by S. Lindeberg et al. (2007) Diabetologia 50(9):1795-1807. doi:10.1007/s00125-007-0716-y.Beneficial effects of a Paleolithic diet on cardiovascular risk factors in type 2 diabetes: a randomized cross-over pilot study by T. Jönsson et al. (2009) Cardiovasc. Diabetol. 8:35. doi:10.1186/1475-2840-8-35.A paleolithic diet is more satiating per calorie than a mediterranean-like diet in individuals with ischemic heart disease by T. Jönsson et al. (2010) Nutr. Metab. (Lond). 7:85. doi:10.1186/1743-7075-7-85. Conversely, popular forms of the diet, for example, those advocated by paleo bloggers, commonly diverge from this. Recently there has been a significant movement towards "Paleo 2.0", which rejects simply eating the foodstuffs of the paleolithic, in favor of eating whatever foods are imagined to reproduce the "evolutionary metabolic milieu".Paleo 2.0 — A Diet Manifesto by Kurt Harris (March 30, 2011 at 8:04 PM) Archevore (archived from December 19, 2011).Paleo 2.0, a rational response to inanity by Melissa McEwen (04/04/2011 — 21:17) Hunt Gather Love(archived from July 30, 2012).Fatty Meat, Potatoes, Dairy And Paleo 2.0 Paleo Leap (archived from May 7, 2011). A simple example is that while Paleo 1.0 would reject cream as a novel foodstuff, Paleo 2.0 would tend to embrace it as a close analog of animal fat. Paleo 2.0 is also more likely to embrace biochemical and dietary research that is extraneous to pure paleo reasoning: as such Paleo 2.0 is more accepting of both extreme low carb and high fat diets, high starch diets, traditionally prepared grains, inclusion of dairy, etc.
==Description==
In its original form, the paleo diet was a combination of two popular fad diets: the low-carb diet and the gluten-free diet. More recently, however, many paleo proponents are moving away from low-carb,Synthesis: Low-Carb and Food Reward/Palatability, and Why Calories Count by Richard Nikoley (February 29, 2012) Free the Animal. citing such modern societies as the Kitava People of Papua New Guinea who do practice agriculture and have a diet mainly consisting of tubers, fruit, fish and coconut.The Kitava Study by Staffan Lindeberg (archived from November 1, 2007).Cardiovascular risk factors in a Melanesian population apparently free from stroke and ischaemic heart disease: The Kitava study by Staffan Lindeberg et al. (1994) Journal of Internal Medicine 236:331-340. The life expectancy for the Kitavans is only 45 years but this is mainly due to high infant mortality from malaria and other infections; excluding infant mortality, the life expectancy is unknown. Lindeberg's team looked at a specific set of health endpoints (blood pressure, anthropometry and serum lipoproteins) and noted that they might explain the apparent lack of stroke and heart disease. Harriet Hall concluded from the Lindeberg team results, "The Kitava Study provides food for thought; it doesn't provide enough justification to recommend either a Kitavan diet or a standard 'Paleolithic diet' over other healthy diets."What Can We Learn from the Kitavans? by Harriet Hall (September 10, 2013) Science-Based Medicine.
Paleo diet fans call the foods they avoid "neolithic" foods as they did not come into widespread human consumption until the agricultural revolution, despite ample evidence that humans have been cooking wild potatoes, corn, legumes, and a variety of sugars for at least 400,000 years. A problem with refuting or supporting a diet based on prehistoric humans is that details are, well, prehistoric. The history of cooking is, like most studies of ancient humans, highly controversial. The earliest dates suggested by scholars are 2 million years ago.1000 Inventions and Discoveries by Roger Bridgman in association with the Smithsonian A very small minority suggest that cooking began just 40,000 to 10,000 years ago with the advent of agriculture. Most scholars accept some middle ground of 400,000 - 200,000 years ago.Did Cooked Tubers Spur the Evolution of Big Brains? by Elizabeth Pennisi (1999) Science 283(5410):2004-2005.
Much of the Paleo diet movement is focused not on the work of anthropologists but on that of Weston Price regarding the effects of modern (1920s-1930s) processed food on so-called primitive cultures who were seen as "living fossils" of neolithic societies.
==What do paleo dieters eat?==
As with any fad diet, the paleo diet comes in many varietiesThe Many Types of Paleo by Joel Runyon (June 3, 2013) ''Ultimate Paleo Guide. and ranges widely. In general, though, the following food guidelines should hold true:
* Meat, especially birds, wild-caught fish, and grass-fed ruminants. Variation exists among paleo belief as to how fatty paleolithic meats would have been.The Paleo Diet: Lose Weight and Get Healthy by Eating the Foods You Were Designed to Eat by Loren Cordain (2010) John Wiley & Sons; Revised edition. ISBN 0470913029.What Is The Paleo Diet? by Robb Wolf (archived from 16 Apr 2019 17:10:47 UTC).The Archevore Diet by Kurt Harris (9/13/2011) '"Archevore (archived from September 30, 2011). Hunter-gatherers living in coastal areas would likely have eaten reasonable amounts of fat from marine mammals they hunted as the Inuit do today. Others would have eaten less animal fat.
* The offal of the animals listed above.
* (whale skin and blubber) presumably, though probably not outside of Alaska.
* Large amounts of vegetables.
* Fruits (limited by some). 
* Tubers, such as sweet potatoes and sometimes white potatoes (limited by some).
* Butter, lard, tallow, coconut oil, and other fats and oils not made from grains or seeds.
* Fermented foods such as sauerkraut, kombucha, and kefir.
* No added sugar, especially high-fructose corn syrup. (However, some dieters commonly use sweeteners such as dried fruits, coconut, maple, and agave syrup)
* No grains or legumes, though some argue that soaking and/or fermenting them makes them acceptable.Are Traditionally Prepared Grains Healthy? by Mark Sisson (August 03 2011) Mark's Daily Apple (archived from October 9, 2018).
* Dairy is often excluded or limited, but high fat or fermented dairy is often included by so-called 'lacto-paleos' or 'Primal'.The Argument for Lacto-Paleo (January 13, 2010 at 10:12 pm) A Tribe Called Fit (archived from April 13, 2015).The Argument for Lacto-Paleo (January 13, 2010 at 10:12 pm) A Tribe Called Fit.
As with any woo, adherents vary as to how extremely they take it, from just cutting out processed foods, to fully cutting out all grains and dairy, to those who only eat things they can gather themselves, either directly, though hunting, gardening, etc., or indirectly, through local hunters and farmers or online stores. For some purists, even things like tomatoes are off limits despite being something that can be "gathered", because they were not known to be consumed by paleolithic man. Eggs are allowed because they are theoretically something that can be gathered in the wild. Alcoholic beverages tend to be avoided because beer and most liquor are produced from grain and require processing, but small amounts of unpalatable wine could in theory be "found" in naturally fermented foodstuffs. Actual wine and beer likely did not start until near the time of the advent of agriculture, i.e., post-paleolithic.Wine grapes were first domesticated 11,000 years ago, gene study says: ‘The grapevine was probably the first fruit crop domesticated by humans’ by Joel Achenbach (March 2, 2023 at 2:00 p.m. EST) The Washington Post.According to the authors of a new study, the discovery marks the earliest-known evidence of beer production among ancient peoples by Brigit Katz (September 13, 2018) Smithsonian Magazine. Honey and stevia are some of the most commonly allowed sweeteners, though some also include maple syrup. However, a critic might delight in reminding any paleo dieter that you must boil sap to get syrup, and the technology to have something to boil in is "new" in human history. In practice, this diet is most often high in animal products and vegetables, though vegetable-intensive versions with meat limited to wild game are followed. There are also raw foodist variations. A paleo-style diet is generally time-consuming to "gather" (even if it's just at the local supermarket) and prepare, just as any other diet that cuts out processed foods.
Small numbers of paleo dieters try a veganVegan Paleo Diet by Lindsay S. Nixon, Happy Herbivore (archived from August 11, 2016). or vegetarian versionHow to Follow the Paleo Diet Without Eating a Single Piece of Meat by Matt Frazier (October 12, 2010) No Meat Athlete (archived from November 15, 2018). of the diet though most humans can only get vitamin B12 from animal products or from highly processed vitamin supplements.What Every Vegan Should Know About Vitamin B12 by Stephen Walsh (2011) The Vegan Society (archived from October 17, 2018).
==What did paleolithic humans actually eat?==
Paleolithic humans adapted their diet depending on the season and on what food resources were available locally. Humans evolved to be flexible eaters.Why the Paleo Diet Is Half-Baked. We are not biologically identical to our Paleolithic predecessors, nor do we have access to the foods they ate. And deducing dietary guidelines from modern foraging societies is difficult because they vary so much by geography, season and opportunity. by Ferris Jabr (June 3, 2013) Scientific American. Studies of modern foragers indicate a wide range of diets, suggesting a similarly wide range among paleolithic peoples. Inuits subsist almost entirely on meat (and blubber); others living by the sea often eat mostly fish and shellfish; those away from the sea but with access to tubers or other vegetables or fruit will eat them.Trying the Hadza hunter-gatherer berry and porcupine diet, BBC Magazine, 23 July 2017Hunter-gatherer diets—a different perspective by Katharine Milton (2000) The American Journal of Clinical Nutrition 71(3):665–667. doi:10.1093/ajcn/71.3.665. Early stone tools were used to process both animal and plant material.Oldowan and Acheulean Stone Tools, Museum of Anthropology, University of Missouri (archived from December 15, 2015). Mixing foods up from different parts of the world is a post-Paleolithic invention.
Actual Paleolithic diets had to include animals and plants that most Americans (who are the primary consumers of paleo woo) wouldn't touch with a 10-foot squeamish pole. Next time you meet a paleo, ask them if they eat:
* Each other (and possibly Neanderthals) given that there is evidence of cannibalistic scavenging and even direct cannibalism among early human ancestors. 
* Small game — really small game — like rats, mice and squirrels.
* Unpleasant plants, pre-selective breeding. Less-attractive versions of the nuts you find in your ice cream.Achewood, "Ray Is Paelo", January 15, 2016 Sour and bitter tastes existed in many plant foods before human interference. Although paleolithic humans probably avoided downright foul-tasting (and likely poisonous — the dose makes the poison) food, the plants that they ate were hardly nice, friendly spinach or carrots. Many modern vegetables are more pleasant mutations and hybridizations of less pleasant or even poisonous plants such as are found in the genera Solanum (tomatoes, potatoes, peppers, eggplants) and Prunus (almonds, peaches, apricots, plums, cherries), and even bananas, which were formerly mostly seed. If you hated Brussels sprouts and broccoli as a kid, imagine how nasty they were before selective breeding, not that it would be better if you loved them too (sprouts, like other Brassica — cabbage, broccoli, cauliflower, kale, etc. — are the result of centuries of modification of the wild cabbage). Carrots were only grown for their leaves until around 1000 years ago, and orange varieties date from about 1600.Wesley Fenlon, Why the Carrot is Orange: Blame the Prince of Orange. Archived from tested.com, 10 April 2012. Many fruits, such as oranges, strawberries, and bananas have been greatly modified by hybridization and selective breeding to produce versions with smaller seeds, more fruit, and less bitterness (strawberries date to the 1750s). Safe varieties were likely discovered by just eating them and hoping it didn't kill anybody. They may have played "will it kill me" with wild fungi, but modern mushrooms (common/button, chestnut, portobello, and more) derive from a variety first cultivated in 1707 CE.
* Woody stems, stripped bark, and pith: things suspiciously absent from the modern paleo diet that probably contributed to the extreme dental wear and tear observed in fossil individuals.
* Organ meat — a critical part of paleolithic human's diet. Does the average paleo dieter (likely American) eat brains, tongues, stomach, eyes, liver, or kidneys? All of these brought important nutrition to our "healthy" ancestors that doesn't exist in white meat and cuts of grazing beef (which the animals themselves were selectively bred for eating and are different from their ancestors).
* Putrid meat, both raw, fermented or cooked — Historical accounts of hunter-gatherers and present-day hunter-gatherers in the modern-day arctic have relished eating putrid meat and fish.Stone Age Cuisine: The realization that people have long eaten putrid meat has archaeologists rethinking ancient diets by Bruce Bower (March 25, 2023) Science News.Putrid Meat in the Tropics: It Wasn't Just For Inuit by John D. Speth & Eugène Moran (2022) PaleoAnthropology 2022:2:327−338. doi:0.48738/2022.iss2.114.
* Chyme — the stomach content of herbivores
* Insects, especially grubs, beetles, and cockroaches
* Lizards, newts, frogs, turtles and anything else that had meat on its bones
* Grains and other starches such as sorghum, wild corn (in both North and South America; they look nothing like the domestic type), potatoes (South America), and a large variety of seeds. Evidence for consumption of legumes such as wild lentils has also been found, along with stone tools associated with processing them.Middle Stone Age starch acquisition in the Niassa Rift, Mozambique by Julio Mercader et al. (2008) Quaternary Research 70:283-300 (archived from October 28, 2014).Thirty thousand-year-old evidence of plant food processing by Anna Revedin et al. (2010) PNAS 107(44):18815-18819. doi:10.1073/pnas.1006993107. There is also evidence that paleolithic humans evolved extra amylase production to break down cooked starches, such as tubers, long before the advent of agriculture, suggesting that starchy food was already a diet staple.The Importance of Dietary Carbohydrate in Human Evolution by Karen Hardy et al. (2015) The Quarterly Review of Biology 90(3):251-268. doi:10.1086/682587.Genome flux and stasis in a five millennium transect of European prehistory by Cristina Gamba et al. (2014) Nature Communications 5:5257. Evidence of oat flour production more than 32,000 years old has been found (despite oatmeal being a big no-no on a lot of paleo diets). The oldest remains of bread dated to around 14,000 years ago, well before the birth of agriculture.A bit stale by now: world’s oldest bread discovered, Cosmos Magazine, 17 July 2018
* Fruits and nuts
* Shellfish
If paleo advocate responds with "No, I don't eat some of that stuff," you've cornered them. They'll tell you that they don't eat insects because that would disgust them, but the real reason is that they have a faulty understanding of evolutionary reality, and if you want to act a little pretentious, you can also argue they don't appreciate the broad palate humans historically have. Or if you just like grossing people out, tell them that if they're eating fruits or vegetables that they're already eating insects, they're just not seeing them.I Hate to Break it to You, but You Already Eat Bugs by Kyle Hill (June 5, 2013) Scientific American.
==How high-protein diets can work==
The paleo diet, with its emphasis on meat consumption, is naturally amenable to a high protein intake. High protein diets, such as the South Beach Diet and Atkins Diet, are popular for weight loss and have attracted a large amount of research.Protein, weight management, and satiety by D. Paddon-Jones et al. (2008) Am. J. Clin. Nutr. 87(5):1558S-1561S. doi:10.1093/ajcn/87.5.1558S.Benefits of high-protein weight loss diets: enough evidence for practice? by B. J. Brehm & D. A. D'Alessio (2008) Curr. Opin. Endocrinol. Diabetes Obes. 15(5):416-21. doi:10.1097/MED.0b013e328308dc13.
Some reasons high protein diets work:
# When eating protein, the brain sends a hormone called leptin that tells the stomach to stop eating. Studies show that people who include a significant portion of their meal as protein (30-50%), will not desire food, especially "snacks", for longer periods of time. What exactly causes this is not fully understood.Soybean β-conglycinin bromelain hydrolysate stimulates cholecystokinin secretion by enteroendocrine STC-1 cells to suppress the appetite of rats under meal-feeding conditions by K. N. Sufian et al. (2011) Biosci. Biotechnol. Biochem. 75(5):848-53. doi:10.1271/bbb.100765.Neuropeptites and the regulation of appetite by J. . Parker & S. R. Bloom (2012) Neuropharmacology 63(1):18-30. doi:10.1016/j.neuropharm.2012.02.004.Food for thought: the physiological relevance of ghrelin and dopamine D2 receptor heterodimerization in the regulation of appetite by A. Salahpour & M. G. Caron (2012) Neuron 73(2):210-1. doi:10.1016/j.neuron.2012.01.004.
# Eating protein causes diet-induced thermogenesis (DIT), a shift in the metabolism of the body, which helps increase the amount of weight loss for dieters. However, one of the most effective types of protein to create this shift is the milk proteins, something not allowed in the paleo diet.Effect of milk proteins on DIT
# The texture of meat and the associated work done by the jaw produces more sense of satiation. 
# Protein and fat take longer to digest, leaving the dieter with a sensation of being "full" for a longer period of time.Digestion rates of carbohydrates in women by L. J. Ells et al. (2005) Br. J. Nutr. 94(6):948-55.Young Voices: Life with Diabetes. Lesson 2: Digestion of fats, proteins, and carbohydrates by Mark Brady et al., Discovery Education (archived from December 25, 2011).
# Simple carbohydrates, specifically processed sugars, cause insulin peaks and crashes, causing the dieter's body to react with a mental desire to eat, and often a physical sensation of being tired, weak or shaky.Return of hunger following a relatively high carbohydrate breakfast is associated with earlier recorded glucose peak and nadir by Paula C. Chandler-Laney (2014) Appetite 80: 236–241.
Nevertheless, it is worth noting that the paleo diet, even in a 'high meat' form, is not necessarily high in protein. While meat is obviously protein rich, by excluding grains and dairy, the paleo diet removes significant sources of protein in the standard Western diet. For example, a 2500 kcal diet based exclusively on whole-wheat breadNutrition Facts: Bread, whole-wheat, commercially prepared (2014) Self, Nutrient data for this listing was provided by USDA SR-21 (archived from April 13, 2015). will provide more protein than 1-½ pounds of beef steak.Nutrition Facts: Beef, chuck, blade roast, separable lean and fat, trimmed to 1/8" fat, all grades, raw (2014) Self, Nutrient data for this listing was provided by USDA SR-21 (archived from April 13, 2015). Various dietary trials of paleo diets show little if any difference in protein intake between diet groups.Beneficial effects of a Paleolithic diet on cardiovascular risk factors in type 2 diabetes: a randomized cross-over pilot study by Tommy Jönsson et al. (2009) Cardiovasc. Diabetol. 8:35. doi:10.1186/1475-2840-8-35. One study also found the paleo diet produced more satiety per calorie, compared to a Mediterranean diet, which was not accounted for by differences in protein intake.A paleolithic diet is more satiating per calorie than a mediterranean-like diet in individuals with ischemic heart disease by Tommy Jönsson et al. (2010) Nutrition & Metabolism 7:85. doi:10.1186/1743-7075-7-85.
Paleo diets, in contrast to high protein diets such as the Atkins Diet and the South Beach Diet, also include relatively high quantities of fiber, which, like protein, adds to satiety.A Satiety Index of common foods by S.H.A. Holt et al. (1995) European Journal of Clinical Nutrition 49(9):675-90.
==Evaluation of claims==
Losing weight can be hard. In the modern world, we sit most of our work day, drive or ride a bus home, use elevators and escalators to ascend, and have so many websites to surf. We have to "work in" our exercise, and schedule trips to the gym usually between January 2 and January 15. We have little time or desire to cook, so we eat crap, drink liquid sugar, and give in to cravings because the convenience store is just around the corner. For these reasons, dieting offers much scope for scams and woo; semper caveat emptor. Does the paleo woo work, and is it based on science? 
An expert summary of the peer-reviewed scientific evidence for and against the paleo diet found that "the Paleo diet is not a miracle diet and several of the premises of the Paleo diet are not supported by evidence." The Popular Paleo Diet by Tanis Fenton (Nov. 2014; Revised Oct.2017) Practice-based Evidence in Nutrition, Dietitians of Canada.
===Nutritional claims===
Loren Cordain, Ph.D., author of a version of this diet, Exercise Physiology,Loren Cordain, Ph.D. The Department of Health and Exercise Science, Colorado State University (archived from October 7, 2011). claims that the diet is as healthy in nutrition as you can get.The Paleo Diet: Lose Weight and Get Healthy by Eating the Food You Were Designed to Eat by Loren Cordain (2002) Wiley. ISBN 0471267554. It is important to note at the outset that Cordain is an exercise physiology specialist, not a dietician — while not a novice in the field, his expertise is tangential to the topic. Some of his advice is dubious. Cordain advises making a salad, storing it and eating a bit with extras every day for a week. By day two the salad will have lost its vitamin content; by the end of the week there may be a dose of the germs, a real-hunter gatherers' encounter. Here is what a website that understands food hygiene recommends. "Store leftovers in the fridge within two hours of cooking and eat them within three days."Fridge Hygiene SafeFood. A website that understands food hygiene advises against storing prepared food for a week. A bout of food poisoning could lead to dramatic weight loss as claimed. 
Cordain and other advocates argue that due to the restrictions of his diet and the satiety afforded by the allowed foods, dieters consume fewer carbs (especially simple carbs such as sugar), and fewer calories total. Indeed, research shows that a diet limited in sugar and processed foods (which the paleo diet necessarily is, since processing is a neolithic thing) will generally help you lose weight. Grains, especially bread and desserts, are top sources of calories in America.Dietary Guidelines for Americans 2010 U.S. Department of Agriculture. Cutting them out will naturally lower one's calorie consumption drastically. Reviewing members of a blog's posts at their siteThe Best Paleo Breakfast Recipes Paleo Breakfast. and putting their day's foods into a calorie calculator shows something hardly surprising: the consumed calories are generally between 1200-1500 kcals, which is what is advised by the USDA for weight loss for women. Granted, one doesn't have to count calories by following this diet, but it's dubious that the weight loss is from the "type" of foods, and not just the amount.
In principle, none of this is unique to eating "paleolithic" foods, and nothing suggests that the body cannot handle foods we've sourced in the last 100,000 years — in proper amounts, at least. But the fact that paleo dieters seem to have an easier time consuming fewer calories than the average American suggests that, in practice, this diet confers some psychological advantages versus a diet high in simple carbs.
Further, those attempting to follow the recommendation of this diet to eat only grass-fed ruminants, pastured poultry, etc., may find it so difficult or expensive that they end up eating the same animals as the rest of us.
It's commonly said that diets boil down to how much energy we take in versus how much we expend. Calories in versus calories out, however, is extremely reductionist, as nutrients and food composition matter more. While it is technically possible to lose weight eating only Twinkies, and gain weight eating only carrots, it is much more difficult since carrots are not calorie dense yet they are more filling by being fiber rich, requiring more time to chew, and requiring more time to digest as opposed to a Twinkie which takes considerably less effort to digest, does not satiate as long, is dense in cheap carbs and sugars, and has no nutrients. Thus, the advantage of a paleo diet, like any other diet that emphasizes unprocessed foods, is in the satiety: dieters can lose weight and stay satisfied without having to meticulously count calories.
In U.S. News and World Report's 2013 annual review of about 30 popular diets, conducted by a panel of around 30 nutrition and medical experts, the paleo diet ranked close to the bottom in 6 different metrics.Paleo Diet: Expert Reviews, last updated by Kurtis Hiatt (January 02, 2013) U.S. News and World Report (archived from November 4, 2013).
===Medical claims===
Cordain has also suggested that because it is generally low in fat, and that wild foods have a generally low glycemic index (also a popular diet buzz word), it will help to prevent illness from "modern diseases" (such as diabetes mellitus type II).The Paleo Diet by Matt McMillen (2018) WebMD. Real food scientists note glycemic load is based on realistic portion sizes and is therefore more significant than glycemic index. The glycemic load from baked potato is as high as that from sugary drinks.Carbohydrates and the Glycemic Load Harvard School of Public Health.International table of glycemic index and glycemic load values: 2002 by K. Foster-Powell et al. (2002) Am. J. Clin. Nutr. 76(1):5-56. doi:10.1093/ajcn/76.1.5.
The stated assumptions at websites that suggest following this diet are that "cavemen were healthier"Paleo Triathlon Diet: Make your Body The Ultimate Performance Machine by Mariana Correa (2015) CreateSpace. ISBN 1507881231. Chapter 1. and did not suffer the kinds of ailments that "Modern Man" suffers from, and that most inexplicable illnesses and disabilities (autism, cancer, arthritis, etc.) come from eating foods the body cannot process.
Despite Cordain's and others' assertions, little evidence exists for the benefits of paleo diets in the scientific journals to support claims that a paleolithic diet prevents acne, "inflammation" (another new woo word in woo medicine) or improves athletic performance. Other authors' claimsPaleoDiet.com — What Our Hunter/Gatherer Ancestors Ate about autism, multiple sclerosis, or arthritis are also unsupported.
Note: Not all variants of the paleo diet are low in fat. Some extol the virtues of saturated fat,E.g., Saturated Fat: Good or Bad? by Kris Gunnars (June 22, 2017) Healthline. particularly in the form of untrimmed red meat, full-fat dairy, and coconut oil. Cordain's assertions about the healthy, low fat nature of "the" paleo diet clearly aren't talking about these high-fat variants.
Paleo diet is effective for heart disease, diabetes, and weight loss. However, it is not more so than any other reasonable low-fat, lower carb diet.The beneficial effects of a Paleolithic diet on type 2 diabetes and other risk factors for cardiovascular disease by David C. Klonoff (2009) J. Diabetes Sci. Technol. 3(6):1229–1232. doi:10.1177/193229680900300601.
Preliminary research on mummies, from ancient cultures around the globe, suggests that rates of atherosclerosis (plaque lining blood vessels) were not significantly lower back then. Randall Thompson, cardiologist and professor at the University of Missouri-Kansas City School of Medicine, states:What ancient mummies tell us about one of the most vexing afflictions of modern life by Peter Whoriskey (December 31, 2015) The Washington Post.
At least one death has been attributed to a high-protein diet, in the case of a woman with a rare genetic disorder (urea cycle disorder).Australian bodybuilder with rare disorder dies eating high-protein diet by Susan Scutti (3:26 PM ET, Tue August 15, 2017) CNN.
===Genetic and evolutionary===
Proponents claim that the human digestive system is adapted to the diet of the paleolithic era and has not evolved since, and that the widespread incidence of diabetes and other diseases can be traced to the shift to a grain-based diet due to the advent of agriculture. This claim is not widely accepted, if at all, within mainstream science. Indeed, evidence suggests that humans have evolved over the last five thousand years specifically to eat an agricultural diet.Hemochromatosis: a Neolithic adaptation to cereal grain diets by C. Naugler (2008) Med. Hypotheses 70(3):691-692.FADS1 and the Timing of Human Adaptation to Agriculture by Sara Mathieson & Iain Mathieson (2018) Molecular Biology and Evolution 35(12):2957–2970. doi:10.1093/molbev/msy180. Further, the basis of the idea that we have not changed genetically does not take into account modern genetic studies nor modern theories of evolution.Ströhle A, Wolters M, Hahn A (January 2007). "Carbohydrates and the diet-atherosclerosis connection—More between earth and heaven. Comment on the article "The atherogenic potential of dietary carbohydrate"". Preventive Medicine 44 (1): 82–4. doi:10.1016/j.ypmed.2006.08.014. PMID 16997359. There is evidence that in Europe, farmers out-competed and eventually replaced hunter-gatherers with minimal interbreeding.Written in bone: Genetic data from ancient Europeans are rewriting the prehistory of the continent by Tina Hesman Saey (May 2, 2014) Science News.
In fact, humans have, only to a certain degree, adapted to a diet based on agriculturally-produced foods. Milk intolerance is a condition where adults cannot digest and absorb lactose. This condition is common in EuropeLactose intolerance and normal in at least some Chinese populations. Over 90% of Chinese adults cannot digest or absorb lactose fully.
Prevalence of primary adult lactose malabsorption in three populations of northern China by Y. G. Wang et al. (1984) Hum. Genet. 67(1):103-6. doi:10.1007/BF00270566.Dairy Intolerance in China by Emma Hockridge (2007) Foods Matter. China had an agricultural system for thousands of years, but most Chinese adults have not evolved the ability to make full use of the milk that their dairy animals produce.
Towards the end of the Paleolithic era, during the Pleistocene (c. 10,000 BCE), human genes changed in response to increases in cooked carbohydrates in the diet. The effect of this cooking was to increase digestibility of starches, and had the effect of facilitating the increased metabolic demands of larger brain sizes, red blood cells and fetal development.The importance of dietary carbohydrate in human evolution by K. Hardy et al. Q. Rev. Biol. 2015 Sep;90(3):251-68.
Loren Cordain advised against milk based on what he calls "an impressive study", though the author of the studyPlausibility of Dietary Lactose as a Coronary Risk Factor by Jeffrey J. Segall (13 Jul 2009) Journal of Nutritional & Environmental Medicine 12(3):217-229. doi:10.1080/1359084021000006885. and the UK NHS call it a preliminary study which does not provide firm conclusions.Milk may be linked to bone fractures and early death by Bazian (October 29 2014) National Health Service (UK). Cordain suggests eating bone meal to increase calcium intake.Got Bones? The Paleo Solution for Building Strong Bones While Keeping Arteries Soft and Supple However, lead and mercury are present in bones from western nations, and the human variant of mad cow disease could be transmitted through bones.Bone Meal University of Utah Health Care (archived from November 11, 2011). 
Present-day humans cannot go back to a paleolithic-era diet because they do not live in a paleolithic environment. Our foods are different. For people on a Western diet who can digest milk, leaving it out may be harmful. High-protein diets (like some meat-based paleo diets) can lead to the body excreting calcium which gets depleted from bones.China Report: Osteoporosis by T. Colin Campbell (October 29, 1997) T. Colin Campbell Center for Nutrition Studies 
 
Proponents of the paleo diet believe the "caveman diet" is the way humans were intended to eat — ignoring the fact that cavemen used much more energy than a modern human to gather food, and thus evolved a taste for foods with the richest in calories and fat, essentially making the caveman "diet" do the opposite of what it is intended for. In fact, for much of human existence, the wealthy became fat and their obesity was respected as a sign that they could afford to eat well and did not have to perform hard labor. The diet also ignores the fact that scientists have found traces of grains in fire pits from the earliest of humans, as well as evidence from "modern" hunter gatherers that tubers and legumes make up a rich part of their diet.
An interesting question of resource logistics comes up when discussing this diet. According to many scientists familiar with issues of world food supply, such as Norman Borlaug and Lester Brown, it is only because of a grain-based diet that the Earth can sustain 7 billion people.
While not evolutionary strictly speaking, there is evidence that the effect of eating an agriculture-based diet has an effect on dental overbite. Hunter-gatherers tend to have top and bottom teeth that align whereas agriculturalists tend to have an overbite with the top row of teeth protruding in the front. This would be due to the tougher-to-chew diet of hunter gatherers (game meat and wild plants). One consequence of this is that the languages of agriculturalists tend to have ("f" and "v" in English) in their languages whereas such sounds occur rarely among the languages of hunter-gatherers. Labiodentals are difficult to pronounce without having at least a slight overbite.The rise of farming altered our bite and changed how people talk: Eating softer food preserves a slight overbite that makes it easier to pronounce certain sounds by Bruce Bower (2:00pm, March 14, 2019) Science News. So if you are actually stupid enough to raise your children on an authentic paleo diet, they may not have an overbite when the grow up and may have difficulty pronouncing labiodentals.
===Political===
LewRockwell.com has carried numerous articles promoting the paleo diet to libertarians, on the grounds that a grain, dairy, and sugar based diet is the product of big government and government-privileged agribusiness.The Paleo-Libertarian Connection by Toban Wiebe (June 9, 2010) Lew Rockwell.A Libertarian's Take on the First Ever Ancestral Health Symposium by Karen De Coster (August 15, 2011) Lew Rockwell. On the far left side of anarchism, the diet has some interest among anarcho-primitivists with Lierre Keith's The Vegetarian Myth being the most influential book, arguing that agriculture is harmful to the planet.The Vegetarian Myth: Food, Justice, and Sustainability by Lierre Keith (2009) PM Press. ISBN 1604860804.Are Vegetarians Living a Lie? by Keith Goetzman (5/22/2009 3:57:31 PM) Utne Reader.
Apart from the right and left fringes of anarchism, the diet does have a more mainstream political appeal among those who see it as a blow against political correctness and perhaps as a counter to veganism and vegetarianism. Nourishing Traditions: The Cookbook that Challenges Politically Correct Nutrition and the Diet Dictocrats by Sally Fallon, while not a strictly paleo cookbook (it allows for whole grains, legumes and promotes raw milk), it could be described as semi-paleo and is currently quite popular.Nourishing Traditions: The Cookbook that Challenges Politically Correct Nutrition and the Diet Dictocrats by Sally Fallon (2001) Newtrends Publishing. ISBN 0967089735.
==Woo debunked==
The majority opinion of anthropologists seems to be that any information we have about what our ancestors were eating is insufficient to determine what a diet "based on their lives" would be like. In addition, the paleo diet doesn't make much sense, since diet varied by location as humans adapted to local conditions.Frank W. Marlowe. Hunter-Gatherers and Human Evolution. Evolutionary Anthropology 14:54 – 67 (2005) Further, the same research questions how "healthy" humans could have been 100,000 years ago, when they were dying at a much younger age, generally malnourished (as seen by bone samples and hair samples), and often starving, simply due to the difficulty of acquiring foods.Paleolithic diets: a skeptical view by Marion Nestle (2000) Nutrition Bulletin 25(1):43-47. doi:10.1046/j.1467-3010.2000.00019.x. Atherosclerosis was less common in primitive societies than in industrial societies but it happened. Surviving long enough to develop atherosclerosis was also far less common in hunter gatherer societies. 
Basing one's diet on people who were often starving, had to spend days tracking and hunting for the foods they ate, who would eat almost anything during the harshest of times, and had short lifespans, high infant mortality, and generally harsh lives seems a bit extreme for simply losing weight, and is very likely fully unhealthy. At a minimum, it must be admitted that paleolithic humans had eating habits and requirements that were dramatically different from modern humans, who exist in an environment that is much more rich in available calories, leisure time, variety of foods, and lifespan. Because of this essential logical difficulty and the dearth of research support, eating like a prehistoric person is not likely to be the healthiest option.
Assumptions about paleo diets commit a fallacy which is common in nutrition, namely to assume that a person or group's diet, in isolation from their lifestyle, is responsible for their state of health. Even if we did assume that paleolithic humans had a diet which was ideal for them (although all evidence suggests otherwise, as described above), applying the same diet to a modern lifestyle would not necessarily be ideal. In other words, if you want to have the health of a caveman (and why would you?), you have to live like a caveman, not just eat like one.
==In a nutshell==
For those of you who can't see embedded YouTube, here is the link
==See also==
*Appeal to nature
*Blood type diet
*Diet woo
*Food woo
*Golden age
*Low-carb diet
*Neolithic Revolution
*Raw foodism
*Urban caveman movement
*Veganism
==External links==
*The "True" Human Diet Peter Ungar April 17, 2017 Scientific American
*Must-Read review — if only for her humor
*The Paleo Diet: Caveman Cure-All or Unhealthy Fad?, The Atlantic
*Paleo Diet Food List Simple Paleo Diet Food List
*Against All Grain — not strictly Paleo, but they share the "all grains are evil" mentality
*Plant Positive Videos refuting inaccurate/misread research perpetuated by the Paleo blogosphere, Gary Taubes, etc.
==Notes==
==References==
Category:Alternative medicine
Category:Diet woo