Ancestors
Some of our ancestors ate little to no meat
150g+Fiber per day in pre-agricultural samples
Before farming, people ate far more fiber than we do today, a sign of a diet heavy in plants[4][6]. Some Neanderthals ate no meat at all[1], and others cooked plants[3]. Hundreds of thousands of years ago, people were already processing dozens of food plants[9]. The caveman who lived on meat alone is mostly a modern myth.
What the evidence says
The main points first. Every claim is tied to a source below.
Dental plaque shows some Neanderthals ate no meat
For a paper in Nature, Weyrich and colleagues sequenced DNA from Neanderthal dental plaque[1]. The Neanderthals at Spy in Belgium ate rhinoceros and sheep[1]. The ones at El Sidrón in Spain showed no sign of meat at all, only split-gill mushrooms, pine nuts, and forest moss[1]. Not all Neanderthals were vegan[1], but some living in a forest got by without killing animals[1], and their teeth don’t fit the idea of a meat-only caveman[1].
Read full article →Neanderthals cooked plants, and the starch is still on their teeth
In a 2011 PNAS paper, Henry, Brooks, and Piperno reported cooked starch grains from Neanderthal dental plaque in Iraq and Belgium, from date palms, legumes, and grass seeds[1]. Many of the grass-seed starches had the kind of damage that cooking causes[1], so Neanderthals were heating plants on purpose and eating them[1]. A review of 17 sites found 61 kinds of plants from 26 plant families that Neanderthals used for food, medicine, and more[2].
Read full article →Some ancient people ate about 150–225 grams of fiber a day, and most people now eat about 15
Leach and Sobolik analyzed prehistoric stool samples from the Chihuahuan Desert[1]. The people there ate roughly 150–225 grams of fiber a day[1], including about 135 grams of inulin-type prebiotics from agave, sotol, mesquite, prickly pear, and onion[1]. Coprolites (preserved feces) from Mexico, Peru, and rural Africa show similar amounts, more than 100 grams a day and sometimes around 120[2]. Separate estimates by Eaton and Konner put late Paleolithic fiber intake at around 100 grams a day or more[3][4]. Intakes like that can’t come from animal products, because fiber comes from plants[2][3].
Read full article →780,000 years ago, humans ate 55 food plants and made tools to process them
At Gesher Benot Ya‘aqov in Israel, the remains of nuts, fruits, seeds, vegetables, and tubers, 55 kinds of edible plants in all, survived from Acheulean humans who lived there about 780,000 years ago[1]. Later work found more than 650 starch grains on basalt hammers and anvils that were used to crack and crush plants such as acorns, wild grasses, legumes, water-lily roots, and water chestnuts[2]. It’s the earliest clear evidence of systematic plant-food processing, and it’s preserved on the tools themselves[2].
Read full article →Mouth bacteria adapted to a starchy diet early in human evolution
Bacteria in the dental plaque of Neanderthals and modern humans share adaptations for binding starch that chimpanzees largely lack[1]. The bacteria in our ancestors’ mouths changed along with a starch-rich diet early in the evolution of our genus, Homo, before Neanderthals and modern humans split[1], so the mouth was already set up for eating plants[1].
Read full article →Articles
Our ancestors ate far more plants than the caveman myth suggests
Fossilized stool shows some prehistoric people eating 150–225 grams of fiber a day, 780,000-year-old stone tools still carry plant starch, and some Neanderthals left no trace of meat in their dental plaque. The caveman who lived on meat alone is mostly a modern invention.
Read full article →
Sources
Papers and datasets. Each card keeps its caveats, including small samples and single-animal cases.
[1]Nature, 2017 · Small sample
The El Sidrón Neanderthals’ teeth showed no trace of meat
Weyrich and colleagues sequenced DNA from the tartar on Neanderthal teeth. Teeth from Spy, in Belgium, showed rhinoceros and sheep, but at El Sidrón, in Spain, they detected no meat, only mushrooms, pine nuts, and forest moss. It’s a small sample and not a rule for the whole species, but those individuals were eating plants.
[2]The Guardian · Review
The El Sidrón Neanderthals ate pine nuts, mushrooms, and moss
The Guardian’s write-up of the Nature paper says the researchers were surprised to find no meat, although earlier work had already suggested the El Sidrón Neanderthals ate little of it.
[3]PNAS, 2011 · Observational
Neanderthals at Shanidar and Spy cooked and ate plants
Henry, Brooks, and Piperno (PNAS, 2011) found tiny plant remains in the tartar on Neanderthal teeth from Iraq and Belgium, including date palms, legumes, and grass seeds, some of them chemically consistent with cooking. The image of a Neanderthal living on raw meat alone doesn’t fit those findings.
[4]British Journal of Nutrition, 2010 · Observational
Ancient people in the Chihuahuan Desert ate 150–225 grams of fiber a day
Leach and Sobolik studied prehistoric coprolites (fossilized feces) from the northern Chihuahuan Desert and estimated that people there ate about 150–225 grams of fiber a day, including about 135 grams of inulin-type prebiotics from agave, sotol, mesquite, prickly pear, and onion. Americans today eat about 15 grams, roughly a tenth of that.
[5]Paleo Foundation digest of coprolite studies · Review
Fossilized feces from Mexico, Peru, and Africa show over 100 grams of fiber a day
Coprolites, or fossilized feces, from the Ocampo Caves and Tehuacán in Mexico and from Huaca Prieta in Peru suggest people ate more than 100 grams of fiber a day. Studies of rural African coprolites have been read as showing as much as about 120 grams of prebiotic fiber a day. The sites are on different continents, but the figures are of the same order of magnitude, and plants made up most of the stool because they made up most of the diet.
[6]NEJM / Eaton & Konner · Review
Eaton and Konner estimated late Paleolithic diets were about 65% plants
In their reconstruction, published in the New England Journal of Medicine in 1985 and revisited in 1997, Eaton and Konner estimated that late Paleolithic diets were about 65% plant foods, with fiber often over 100 grams a day and vitamin C around 392 milligrams. A meat-only diet can’t provide those amounts.
[7]European Journal of Clinical Nutrition, 2006 · Review
Boyd Eaton put ancestral fiber intake at perhaps 100 grams a day
In 2006, Boyd Eaton estimated that our ancestors ate a lot of fiber, perhaps 100 grams a day, and that their intakes of vitamins, minerals, and phytochemicals were typically several times what people get today. Only a diet heavy in plants gives numbers like those.
[8]Nutrition in Clinical Practice, 2010 · Review
Konner and Eaton still found a high-fiber ancestral diet 25 years later
In their 2010 update, Konner and Eaton’s model of Paleolithic nutrition still has people eating far more fiber than a modern Western diet. Their 1985 reconstruction put ancestral fiber well above 100 grams a day, and the update didn’t walk that back.
[9]PNAS, 2016 · Observational
Early humans ate 55 kinds of food plants at Gesher Benot Ya‘aqov 780,000 years ago
Melamed and colleagues (PNAS, 2016) found remains of 55 kinds of edible plants at Gesher Benot Ya‘aqov, an Acheulean site in Israel, including nuts, fruits, seeds, vegetables, and roots and tubers. Early humans of the Homo erectus grade were already eating a wide range of plants.
[10]PNAS, 2025 · Observational
Stone tools from 780,000 years ago still carry starch from plant foods
Ahituv and colleagues (PNAS, 2025) found more than 650 starch grains on basalt hammers and anvils at Gesher Benot Ya‘aqov, from acorns, grasses, legumes, water-lily roots, and water chestnuts. It’s the earliest clear evidence of people processing plant foods systematically.
[11]Evidence for the Paleoethnobotany of the Neanderthal · Review
Neanderthals used 61 kinds of plants across 17 sites
A review of Neanderthal plant use found 61 plant taxa from 26 families at 17 archaeological sites, used for food, medicine, and other purposes. Neanderthals used plants widely, and not only in the south.
[12]PNAS, 2021 · Observational
Our mouth bacteria adapted to starch before we split from Neanderthals
Fellows Yates and colleagues (PNAS, 2021) found that the mouth bacteria (streptococci) of Neanderthals and modern humans share adaptations for binding amylase, a starch-digesting enzyme, that are largely missing in chimpanzees. So starch-rich foods were likely part of the diet early in the genus Homo, before Neanderthals and modern humans split.
[13]PNAS / Sponheimer et al., 2013 · Observational
Early hominins ate an ape-like plant diet before 3.5 million years ago
Sponheimer and colleagues used carbon isotopes to show that before about 3.5 million years ago, early hominins ate almost only C3 plants (trees, shrubs, and herbs), the same diet as apes. The later shift in diet widened the range of plant foods they ate and wasn’t simply a turn to hunting.