The quick version: The paleo diet is an eating plan built on foods people could hunt or gather before farming: meat, fish, eggs, vegetables, fruit, nuts and seeds. It cuts grains, legumes, dairy, refined sugar and processed food. Trials show short-term drops in waist size and triglycerides; long-term benefits are not proven.

👉 Free tool: TDEE & Macro Calculator

👉 Check any food instantly with our free Is It Paleo? Food Checker

If you’re new to the paleo diet, start here. This guide covers what paleo is, exactly what to eat and what to avoid, where the idea came from, what the clinical trials actually found, and quick answers to the most common “is this food paleo?” questions — plus links to our deeper guides when you’re ready to go further.

What is the paleo diet?

Paleo (short for “Paleolithic”) is an eating pattern based on the foods available to humans before agriculture. The core idea is simple: favor whole, minimally processed foods our bodies evolved to handle, and skip the grains, legumes, dairy, and refined products that became staples only after farming began. In everyday terms, most people experience paleo as “real food, no packaged junk, no bread or pasta.” People choose it for steadier energy, better digestion, reduced inflammation, and weight management.

Who came up with the paleo diet?

The idea is older than the name. Gastroenterologist Walter Voegtlin argued for a meat-heavy “Stone Age” diet in his 1975 book The Stone Age Diet. The modern version traces to a 1985 New England Journal of Medicine paper, “Paleolithic nutrition,” by Stanley Boyd Eaton and Melvin Konner, which proposed that a mismatch between modern food and human biology helps drive diseases such as obesity and type 2 diabetes (Eaton & Konner, 1985). Health scientist Loren Cordain popularized the term with his 2002 book The Paleo Diet (history summary).

Different authors draw the line in different places. Eaton and Konner’s later book described a diet that was about 65% plant-based, while Cordain’s version leans more on animal foods. That is why you will see “strict paleo”, “primal” (some dairy) and the stricter autoimmune protocol all described as paleo.

What is the 85/15 rule?

The 85/15 principle, from Cordain’s The Paleo Diet organization, means about 85% of your meals follow paleo rules and about 15% don’t. It exists to make the diet sustainable rather than all-or-nothing (The Paleo Diet: the 85/15 principle). If you eat three meals a day, that works out to roughly three non-paleo meals a week.

What you eat on paleo

  • Quality protein: meat, poultry, fish, seafood, and eggs
  • Vegetables: leafy greens, cruciferous veg, and colorful vegetables of all kinds
  • Fruit: berries, apples, bananas, and other whole fruit (lower-sugar fruits if you’re watching carbs)
  • Healthy fats: avocado, olive oil, coconut, and animal fats
  • Nuts and seeds: almonds, walnuts, macadamias, pumpkin seeds (not peanuts — those are legumes)
  • Starchy tubers: sweet potatoes and other roots, especially if you’re active

What paleo leaves out

  • Grains: wheat, rice, oats, corn, and anything made from them (bread, pasta, cereal)
  • Legumes: beans, lentils, soy, peanuts, and chickpeas
  • Dairy: milk, cheese, and yogurt (a flexible “primal” approach allows some)
  • Refined sugar and processed food: sodas, candy, and most packaged snacks
  • Industrial seed oils: soybean, corn, and similar refined oils

Paleo’s case for dropping grains, legumes and dairy rests mainly on evolutionary reasoning rather than long-term clinical trials, and legumes and whole grains still feature in many mainstream healthy-eating patterns. Paleo is also not automatically low-carb: fruit, sweet potatoes and other root vegetables are all on the menu.

Paleo vs other popular diets at a glance

Paleo compared with other popular diets
Diet Grains? Dairy? Legumes? Carb level
Paleo No Usually no No Moderate (fruit, roots)
Keto No Yes No Very low
Whole30 No No No Moderate
Mediterranean Yes (whole) Some Yes Moderate to high

Whole30 is close to a strict 30-day version of paleo that also drops natural sweeteners, while keto is defined by a very low carbohydrate target rather than by food origin. For deeper comparisons, see Paleo vs Other Diets.

How to start paleo in 5 steps

  1. Clear the obvious non-paleo staples — bread, pasta, cereal, and sugary snacks.
  2. Build each meal around protein plus vegetables and a healthy fat.
  3. Find your swaps — cauliflower rice for rice, lettuce wraps for bread, almond butter for peanut butter.
  4. Plan a few default meals so you’re never stuck deciding when hungry.
  5. Give it 30 days before judging results, then reintroduce foods deliberately to see how you feel.

What does the research say about the paleo diet?

The evidence is real but thin: a handful of small randomized trials, most lasting six months or less. Here is what the two most-cited ones measured.

Key paleo diet trials and what they found
Study Who and how long Result vs comparison diet
Manheimer et al., 2015 (meta-analysis, Am J Clin Nutr) 4 randomized trials, 159 people with at least one metabolic-syndrome marker; outcomes at 6 months or less Waist −2.38 cm, triglycerides −0.40 mmol/L, systolic blood pressure −3.64 mm Hg more than guideline-based diets. No trial measured long-term disease outcomes.
Mellberg et al., 2014 (2-year randomized trial, Eur J Clin Nutr) 70 obese postmenopausal women, average age 60 Fat mass −6.5 kg vs −2.6 kg at 6 months (a clear difference), but −4.6 kg vs −2.9 kg at 24 months (difference no longer significant). Triglycerides stayed lower at 24 months.

Is the paleo diet healthy long term? Nobody knows yet. The trials show an early edge for weight and blood fats that narrows by year two, and the authors of both studies say longer research is needed. The main downside to plan for is nutrient gaps: Harvard’s Nutrition Source notes that dropping dairy and whole grains can raise the risk of low calcium, vitamin D and B vitamins unless you replace them, and that it takes five or more daily servings of foods such as collard greens or canned bone-in fish to cover calcium needs without dairy (Harvard paleo diet review). Our guide to closing paleo nutrient gaps shows how, and paleo diet pros and cons covers the trade-offs in more depth.

If you have diabetes, kidney disease or high cholesterol, or take medication, talk with your doctor or a registered dietitian before switching.

Is it paleo? Quick food answers

One of the most common questions for beginners is whether a specific food fits. Our growing food-by-food guide gives you the verdict, the reason, and paleo-friendly swaps:

Explore our complete paleo guides

Paleo diet questions people ask most

What is the paleo diet in simple terms?

It means eating mostly whole foods that could be hunted, fished or gathered: meat, fish, eggs, vegetables, fruit, nuts and seeds. You skip grains, beans and lentils, dairy, refined sugar and packaged food. It is defined by food type, not by calorie or carb targets.

Who created the paleo diet?

Walter Voegtlin proposed a Stone Age diet in 1975, and Stanley Boyd Eaton and Melvin Konner set out the modern scientific case in a 1985 New England Journal of Medicine paper. Loren Cordain popularized the name with his 2002 book The Paleo Diet.

What is the 85/15 rule on paleo?

It is a flexibility rule from The Paleo Diet organization: about 85% of meals follow paleo and about 15% do not. On three meals a day, that is roughly three non-paleo meals a week, which makes the plan easier to keep.

Does the paleo diet work for weight loss?

In trials it produced more fat loss than standard diets at first. In a 2-year study of 70 women, the paleo group lost 6.5 kg of fat vs 2.6 kg at 6 months, but by 24 months the gap (4.6 vs 2.9 kg) was no longer statistically significant.

Is paleo the same as keto?

No. Keto is defined by a very low carb target and allows dairy. Paleo is defined by food origin, bans dairy, and allows fruit, sweet potatoes and other starchy roots, so it is usually moderate in carbs. See our paleo vs keto comparison for the numbers.

This is general nutrition information, not medical advice. If you have a medical condition or take medication, talk with a doctor or registered dietitian before making big dietary changes.

  • Paleo Diet Constipation: Why It Happens, the Fiber Math for a Paleo Day, and What the Trials Say Helps – Does the paleo diet cause constipation? Why fiber drops when grains and beans go, a USDA-counted day from 8 g to 33 g of fiber, and the foods trials back.


    • Research cited in this guide

    We checked this guide against the nutrition and health sources below. They are worth reading for the underlying detail.