Paleo Diet
An eating pattern recreating a presumed hunter-gatherer diet — it eliminates grains, dairy, and processed food, but evidence for its advantage over other diets is limited and based on small, short studies.
Number of studies
2
Safety
Moderate
Time to effects
Available small studies suggest noticeable changes in metabolic markers within a few weeks — no reliable long-term data.
Who it's for
Table of contents
TL;DR
An eating pattern recreating a presumed hunter-gatherer diet — it eliminates grains, dairy, and processed food, but evidence for its advantage over other diets is limited and based on small, short studies.
- →In small studies and a meta-analysis — short-term improvement in waist circumference, blood pressure, and triglycerides
- →Eliminating highly processed food and added sugar has an independent rationale in the nutrition literature, separate from 'paleo' itself
- →Higher protein and vegetable intake supports satiety
| Type of intervention | An eating pattern based on meat, fish, vegetables, fruit, and nuts; without grains, legumes, dairy, and sugar |
|---|---|
| Evidence level | Preliminary — only small, short-term pilot studies and a few RCTs |
| Target group | People wanting to reduce highly processed food and simple sugars |
| Time to effects | Metabolic markers — improvement within a few weeks in the available small studies |
| Preparation required | A higher budget for meat and fish, meal planning without grains and legumes |
| Status | A popular commercial eating pattern, far less studied than the Mediterranean diet or DASH |
Understand
Overview
The paleo diet is based on foods believed to have been available to humans in the Paleolithic era — meat, fish, eggs, vegetables, fruit, nuts, and seeds — while completely excluding grains, legumes, dairy, refined sugar, and highly processed food. Its rationale is the so-called evolutionary discordance hypothesis: the assumption that the human genome hasn't fully adapted to agricultural products, introduced only about 10,000 years ago.
The available evidence is considerably more modest than for the Mediterranean diet or DASH — it rests on a small number of small, short-term studies. A 2015 meta-analysis showed short-term improvement in waist circumference, blood pressure, and triglycerides versus control groups, but the number and size of included studies were small, and long-term data are practically nonexistent. It's also worth knowing that the very concept is controversial among anthropologists — the actual diet of Paleolithic humans was highly variable by region and season, so today's 'paleo diet' is largely a modern reconstruction, not a historically documented menu.
Who can realistically benefit, and who probably can't? People wanting to reduce highly processed food and simple sugars will benefit regardless of whether they fully follow the paleo rules — that's the core of the real benefit, not a unique effect of this specific pattern. Less likely to benefit are people on a limited budget (a diet based mainly on meat and fish is usually more expensive than one based on grains and legumes), endurance athletes needing readily available carbohydrates, and anyone who excludes whole-grain products and legumes — these have their own solid evidence base of benefits in other, better-studied eating patterns.
History of use
The modern 'paleo diet' was popularized in the early 2000s by physiologist Loren Cordain, based on the evolutionary discordance hypothesis — the assumption that the human genome hasn't fully adapted to agricultural products (grains, dairy), introduced only about 10,000 years ago. Anthropologists and archaeologists point out, however, that the actual diet of Paleolithic humans was highly variable by region and season, and its exact macronutrient composition remains a subject of scientific debate — the modern paleo diet is largely a contemporary reconstruction, not a faithful recreation of a historical menu.
Mechanism of action
A significant portion of the observed effects of the paleo diet probably stem from what it eliminates, rather than from a unique metabolic mechanism: excluding highly processed food and added sugar in itself lowers the caloric density of the diet, and higher protein and vegetable intake increases satiety, making it easier to maintain a caloric deficit.
At the same time, eliminating whole grains and legumes removes significant, well-documented sources of fiber and micronutrients — the net effect therefore depends on whether they're effectively replaced with an adequate amount of vegetables. In the available small studies, no specific biochemical mechanism unique to the paleo diet has been identified that would distinguish it from a general improvement in diet quality relative to the average, highly processed Western diet.
Eliminating highly processed food and added sugar
Genuinely lowers the caloric density of the diet — an effect independent of the rest of the paleo premise.
Higher protein and vegetable intake
Increases satiety, making it easier to maintain a caloric deficit.
Elimination of grains and legumes
Removes documented sources of fiber and micronutrients — requires replacing them with an adequate amount of vegetables.
No mechanism specific to paleo
The observed effects mainly result from a general improvement in diet quality, not from recreating a Paleolithic menu.
Evidence: early-stage — based on 2 studies in this database.
Benefits
Common myths
MythThe paleo diet exactly recreates what people ate in the Stone Age.
FactAnthropologists point out that the Paleolithic diet was highly variable by region and season — the modern 'paleo diet' is a contemporary reconstruction, not a historically documented menu.
MythGrains and legumes are inherently harmful to health.
FactWhole-grain and legume products have their own solid evidence base of benefits in large studies — including in the context of the Mediterranean diet and DASH.
Forms & variants
Paleo Diet comes in several forms that differ in bioavailability and use case — the form you pick genuinely matters for how effective the supplementation is.
Strict paleo diet
No exceptions to the basic principles.
Best for: People who prefer clear, rigid rules
Flexible paleo diet ('primal')
Allows high-quality dairy and small amounts of other otherwise excluded foods.
Best for: Easier long-term adherence to the pattern
Autoimmune paleo diet (AIP)
Additionally eliminates nightshades, eggs, and nuts; used experimentally in autoimmune diseases.
Best for: Only under the supervision of a doctor or dietitian, evidence very limited
Practice
Frequently asked questions
There's no evidence for this — the Mediterranean diet has an incomparably larger evidence base, including large randomized trials like PREDIMED, while paleo relies on small, short-term trials.
That's a premise of the paleo diet, but there's no strong evidence that it's necessary for health — these foods have their own solid evidence base of benefits in other eating patterns.
It can help by eliminating processed food and sugar, but the mechanism is mainly a caloric deficit and higher satiety from protein — there's no evidence of a unique metabolic advantage over other diets with a similar deficit.
Dosage & timing
Typical dose
Not applicable to dosing — an eating model similar to a high-protein, moderately low-carbohydrate diet
Form
Meat, fish, eggs, vegetables, fruit, nuts, and seeds — without grains, legumes, dairy, and refined sugar
Available evidence doesn't confirm an advantage of the paleo diet over other diets of similar quality and caloric deficit over the long term.
Best times to take it
- Not applicable — a full-day eating model
Safety
Side effects & contraindications
Possible side effects
Risk of fiber and certain micronutrient deficiencies when eliminating whole grains and legumes without replacing them with an adequate amount of vegetables
Higher cost of maintaining a diet based mainly on meat and fish
Contraindications
Kidney disease requiring protein restriction — the high-protein variant of the paleo diet may require modification under medical supervision
Endurance athletes with a high need for readily available carbohydrates
Interactions
No specific drug interactions — caution mainly concerns people with kidney disease on a high-protein intake
Is it worth taking?
Who it's for
- People wanting to reduce highly processed food and simple sugars, not necessarily fully following paleo rules
- People with a budget that allows for high meat and fish consumption
Not for
- Kidney disease requiring protein restriction — the high-protein variant of the paleo diet may require modification under medical supervision
- Endurance athletes with a high need for readily available carbohydrates
Evidence
Worth knowing
The term 'paleolithic diet' was popularized in the early 2000s by physiologist Loren Cordain.
Available studies on the paleo diet are small (a dozen to a few dozen people) and short-term, usually under 6 months.
Studies
A meta-analysis of available studies on the paleolithic diet showed short-term improvement in waist circumference, blood pressure, and triglyceride levels compared with control diets, while noting the small number and size of the included study samples.
Manheimer EW et al., American Journal of Clinical Nutrition, 2015
Metabolic and physiologic improvements from consuming a paleolithic, hunter-gatherer type diet
Early-stage evidenceFrassetto LA, Schloetter M, Mietus-Synder M, et al. · European Journal of Clinical Nutrition · 2009
A very small pilot study (n=9) showing short-term improvement in lipid profile and blood pressure after switching to a paleolithic diet.
View studyPaleolithic nutrition for metabolic syndrome: systematic review and meta-analysis
Early-stage evidenceManheimer EW, van Zuuren EJ, Fedorowicz Z, Pijl H · American Journal of Clinical Nutrition · 2015
A meta-analysis of several small studies showed short-term improvement in waist circumference, blood pressure, and triglycerides, while noting the low quality and small number of available studies.
View studySources & bibliography
Citations are illustrative for this demo version and require full bibliographic verification by the editorial team before production publication.
Compare with similar entries
About the authors of this entry
Author
Michał NowakClinical Dietitian
Michał specializes in metabolic nutrition, intermittent fasting and sports supplementation.
61 publications on this site
Medical review
dr Anna KowalczykEditor-in-Chief, Molecular Biology
Anna oversees the editorial process and scientific review of every publication in the knowledge base. She previously researched autophagy and mitochondrial biology.
50 publications on this site
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Comments (2)
- KW
Kasia W. 2 weeks ago
Very clearly explained, especially the interactions section — I hadn't seen it laid out this well anywhere else.
- MT
Marek T. a month ago
Are you planning to update this with the newest study from this year? I saw an interesting meta-analysis.