The Paleolithic diet is a diet based on the premise that if our Paleolithic ancestors
didn't eat it, we shouldn't eat it.
It is based upon everyday, modern foods that mimic the food groups of our ancestors.
Also known as the caveman diet, the Stone Age diet, and the hunter-gatherer diet, it
became popular in the late 2000s, and was Google’s most searched-for weight loss method
in 2013.
The diet is based on several premises, one of which is that our ancestors evolved for
thousands of years and became well-adapted to foods of the Paleolithic era.
Advocates argue that things took a turn for the worse about 10,000 years ago, with the
advent of agriculture and domestication of animals and that our species hasn’t evolved
to properly digest new foods such as grain, legumes, and dairy, much less the highly-processed
and high-calorie processed foods that are so readily available and cheap, and this has
led to modern-day problems such as obesity, heart disease, and diabetes.
Advocates claim that followers of the diet may enjoy a longer, healthier, more active
life, unlike our ancestors.
Critics of the diet point out that we are much more adaptable than previously thought,
that the hypothesis that we are genetically adapted to the Paleolithic environment is
flawed, that it is in any case practically impossible for us to know how our ancestors
ate.
Nutritionists have pointed out that the diet may be less effective than other popular diets
in promoting good health.
History An early book on the topic was The Stone Age
Diet, self-published in 1975 by Walter Voegtlin.
In 1985, Boyd Eaton and Melvin Konner published a paper on Paleolithic nutrition in the New
England Journal of Medicine followed in 1988 by the book, with Marjorie Shostak, The Paleolithic
Prescription.
Since the late 1990s many others have published works promoting the diet, including Staffan
Lindeberg, Mark Sisson, Arthur De Vany.
The diet was overshadowed by regimens such as the Atkins diet and South Beach Diet until
the publication of a popular book by Loren Cordain.
The latter is styled as "Dr Loren Cordain, world's leading expert on paleolithic diets
and founder of The Paleo Movement".
His doctoral degree was in exercise physiology, and he is the owner of the trademark "The
Paleo Diet".
Rationale for the diet
The rationale is that: Human physiology has changed little since
the time our ancestors were hunter-gathers.
Modern humans are adapted to the diet or diets of the Paleolithic period.
The dawn of agriculture and industrialization has led to the availability of foods for which
we are not evolutionarily adapted.
It is possible to understand the ancient diet and reproduce it in modern times, and to learn
from contemporary hunter-gatherers.
Diet is at least in part to blame for diseases of affluence and lifestyle diseases, and that
eaters of forager-style diets do not suffer from them.
Advocates of the diet argue the ancient diet was characterized as follows:
No dairy food.
Very little cereal grains.
Food was not salted.
Lean meat was eaten.
Criticism of the rationale It has been argued that the notion of humans
being unable to adapt to modern food is based on a flawed adaptationistic logic, and that
modern people are adapted to modern foods, since most of the change in the frequencies
of alleles occurs in the first few generations under selection.
For example, research has shown that various populations which have domesticated cattle
have independently developed alleles for dairy tolerance.
It is often argued that preagricultural foragers did not suffer from the diseases of affluence
simply because they did not live long enough to develop them.
With regard to attempts to emulate the "ideal" diet, molecular biologist Marion Nestle argues
that "knowledge of the relative proportions of animal and plant foods in the diets of
early humans is circumstantial, incomplete, and debatable and there are insufficient data
to identify the composition of a genetically determined optimal diet.
The evidence related to Paleolithic diets is best interpreted as supporting the idea
that diets based largely on plant foods promote health and longevity, at least under conditions
of food abundance and physical activity".
Ideas about Paleolithic diet and nutrition are at best hypothetical.
Trying to devise an ideal diet by studying contemporary hunter-gatherers is difficult
because of the great disparities that exist, for example with the animal-derived calorie
percentage ranging from 25% in the Gwi people of southern Africa to 99% in Alaskan Nunamiut.
Food energy excess, relative to energy expended, rather than the consumption of specific foods
may underlie the diseases of affluence.
Studies of traditionally living populations show that humans can live healthily with a
wide variety of diets.
We have evolved to be flexible eaters.
"The health concerns of the industrial world, where calorie-packed foods are readily available,
stem not from deviations from a specific diet but from an imbalance between the energy we
consume and the energy we spend."
The diet
More protein Meat, seafood, and other animal products represent
the staple foods of modern-day Paleo diets, since advocates claim protein comprises 19-35%
of the calories in hunter-gatherer diets.
The Centers for Disease Control and Prevention, the national public health institute of the
United States, recommends that 10-35% of calories come from protein.
Fewer carbohydrates The diet recommends the consumption of non-starchy
fresh fruits and vegetables to provide 35-45 % daily calories and be the main source of carbohydrates.
According to the United States Department of Agriculture, the acceptable macronutrient
distribution range for carbohydrates is 45 to 65 percent of total calories.
A typical modern diet gets a lot of carbohydrates from dairy products and grains, but these
are excluded in the Paleolithic diet.
High fiber High fiber intake not via grains, but via
non-starchy vegetables and fruits.
More fat Advocates recommend, relative to modern diets,
that the Paleolithic diet have moderate to higher fat intake dominated by monounsaturated
and polyunsaturated fats and omega-3 fats, but avoiding trans fats, and omega-6 fats
since saturated fats are considered to have little or no adverse effects upon cardiovascular
disease risk.
Less salt It is well known that modern diets are high
in salt and many diets, including the Paleolithic, recommend a reduction.
Balanced alkaline vs. acid Any food presents either a net acid or alkaline
load to the kidneys.
A good diet strikes a balance.
More micronutrients A higher intake of vitamins and minerals is
recommended via grass-fed meats, fruits, and vegetables rather than grains.
Energy density The Paleolithic diet has lower energy density
than the typical diet consumed by modern humans.
This is especially true in primarily plant-based/vegetarian versions of the diet, but it still holds if
substantial amounts of meat are included.
For example, most fruits and berries contain 0.4–0.8 calories per gram, and vegetables
can be even lower than that.
Game meat, such as cooked wild rabbit, is more energy-dense, but it does not constitute
the bulk of the diet by mass or volume at the recommended plant/animal ratios, and it
does not reach the caloric densities of many processed foods commonly consumed by modern
humans: most McDonald's sandwiches such as the Big Mac average 9 calories per gram, since
there is a high fat content and fat yields 9 cal/gram. and sweets such as cookies and
chocolate bars commonly exceed 4 calories per gram.
Diets with a low caloric density tend to provide a greater feeling of satiety at the same energy
intake, and they have been shown effective at achieving weight loss in overweight individuals
without explicit caloric restrictions.
Even some authors who may appear otherwise critical of the Paleolithic diet have argued
that the high energy density of modern diets, as compared to ancestral or primate diets,
contributes to the incidence of diseases of affluence in the industrial world.
Micronutrient density
Fruits, vegetables, meat and organ meats, and seafood, which are staples of the forager
diet, are more micronutrient-dense than refined sugars, grains, vegetable oils, and dairy
products in relation to digestible energy.
Consequently, the vitamin and mineral content of Paleolithic diet is very high compared
with a standard diet, in many cases a multiple of the RDA.
Fish and seafood represent a particularly rich source of omega-3 fatty acids and other
micronutrients, such as iodine, iron, zinc, copper, and selenium, that are crucial for
proper brain function and development.
Terrestrial animal foods, such as muscle, brain, bone marrow, thyroid gland, and other
organs, also represent a primary source of these nutrients.
Calcium-poor grains and legumes are excluded from the diet.
However, leafy greens like kale and dandelion greens, as well as nuts like almonds, are
very high sources of calcium.
Moreover, components of plants make their low amounts of calcium much more easily absorbed,
unlike items with high calcium content, such as dairy.
Two notable exceptions are calcium and vitamin D, both of which may be present in the diet
in inadequate quantities.
Modern humans require much more vitamin D than foragers, because they do not get the
same amount of exposure to sun.
This need is commonly satisfied in developed countries by artificially fortifying dairy
products with the vitamin.
To avoid deficiency, a modern human on a forager diet would have to take artificial supplements
of the vitamin, ensure adequate intake of some fatty fish, or increase the amount of
exposure to sunlight.
Eating a wide variety of plant foods is recommended to avoid high intakes of potentially harmful
bioactive substances, such as goitrogens, which are present in some roots, seeds, and
vegetables.
Beverages On the Paleolithic diet, practitioners are
permitted to drink mainly water, and some advocates recommend tea as a healthy drink.
Alcohol is not considered "paleo" as our ancestors could not produce drinks containing it; nor
is coffee.
Raw vs. cooked Unlike raw food diets, all foods may be cooked,
without restrictions.
However, there are Paleolithic dieters who believe that humans have not adapted to cooked
foods since the first control of fire by Homo erectus, and so they eat only foods that are
both raw and Paleolithic.
Exclusions Food groups that advocates claim were rarely
or never consumed by humans before the Neolithic agricultural revolution are excluded from
the diet, mainly dairy products, grains, legumes, processed oils, refined sugar, and salt.
Many of these foods would have been available at certain times of the year and may or may
not have been consumed.
Some advocates consider the use of oils with low omega-6/omega-3 ratios, such as olive
oil, to be healthy and advisable.
Cereal grains, legumes, and milk contain bioactive substances, such as gluten and casein, that
have been implicated in the development of various health problems.
Consumption of gluten, a component of certain grains, such as wheat, rye, and barley, is
known to have adverse health effects in individuals suffering from a range of gluten sensitivities,
including celiac disease.
Since the Paleolithic diet is devoid of cereal grains, it is free of gluten.
The paleo diet is also casein-free.
Casein, a protein found in milk and dairy products, may impair glucose tolerance in
humans.
Compared to Paleolithic food groups, cereal grains and legumes contain high amounts of
antinutrients, including alkylresorcinols, alpha-amylase inhibitors, protease inhibitors,
lectins, and phytates, substances known to interfere with the body's absorption of many
key nutrients.
Molecular-mimicking proteins, which are basically made up of strings of amino acids that closely
resemble those of another totally different protein, are also found in grains and legumes,
as well as milk and dairy products.
Advocates of the Paleolithic diet have argued that these components of agrarian diets promote
vitamin and mineral deficiencies and may explain the development of the diseases of civilization
as well as a number of autoimmune-related diseases.
Reception Nutritionists agree that the Paleolithic diet
is beneficial in that it cuts processed foods that have been highly modified from their
raw state such as white bread, artificial cheese, certain cold cuts and packaged meats,
potato chips, and sugary cereals.
These often offer less nutrients than their unprocessed equivalents, and may be packed
with calories, sodium and preservatives that may increase the risk of heart disease and
certain cancers.
A ranking by U.S. News & World Report, involving a panel of experts, evaluated based on factors
including health, weight loss, and ease of following.
In 2014, it tied for last place out of 32 with the Dukan Diet.
Evidence for the effect of the switch to agriculture on general life expectancy is mixed, with
some populations exhibiting an apparent decrease in life expectancy and others an apparent
increase.
And according to S. Jay Olshansky and Bruce Carnes, "there is neither convincing evidence
nor scientific logic to support the claim that adherence to a Paleolithic diet provides
a longevity benefit."
According to the British Dietetic Association the diet excludes key food groups, raising
the potential for nutritional deficiencies.
See also Evolutionary medicine
Inuit diet Modern primitive
Nutritional genomics Paleolithic lifestyle
References