What Is The Paleo Diet?

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A man making a paleo meal in the kitchen

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The Paleo diet is a modern-day take on the dietary pattern of humans living during the Paleolithic or “Old Stone Age” era, which was about 2.5 million years ago. During the Paleolithic era, humans followed a diet that was composed of plants like root vegetables, seeds, nuts, and protein sources such as wild game, seafood, and insects.

The modern-day Paleo diet was popularized by scientist Loren Cordain, who wrote the 2002 book “The Paleo Diet: Lose Weight and Get Healthy by Eating the Foods You Were Designed to Eat,” which outlined Cordain’s take on the Paleo diet and how it can be used to improve overall health.

Because the Paleo diet is based on the diet of people living millions of years ago, it restricts many foods that are common in modern diets, such as grains, legumes, dairy, and added sugar. While the Paleo diet has been linked to a few health benefits—including lowering blood sugar and blood lipid levels—some experts warn that this diet is unnecessarily restrictive.

When following a Paleo diet, your diet will mostly consist of fruits, vegetables, nuts, seeds, and protein sources. Obviously, humans living during the Paleolithic era had more limited food choices than we do now, so the Paleo diet isn’t an exact representation of ancient diets. The Paleo diet is instead used as a way to prioritize nutrient-dense, whole foods while minimizing consumption of ultra-processed foods that are so common in many people’s diets.

Read on to learn more about the Paleo diet, including foods to eat and avoid, and how this eating pattern could impact your health.  

What You Can Eat

When following a Paleo diet, you’ll prioritize whole, nutrient-dense foods. 

According to some research, a Paleo diet provides around 35% of calories from carbohydrates, 35% from fats, and 30% from proteins, which is considered a low-carb way of eating.

The following foods are allowed on the Paleo diet:

  • Meat and poultry: Beef, lamb, pork, chicken, duck, and turkey 
  • Eggs: Whole eggs and egg whites
  • Seafood: Salmon, cod, trout, sardines, clams, mussels, and shrimp
  • Vegetables: Greens, artichokes, zucchini, asparagus, butternut squash, carrots, sweet potatoes, and broccoli
  • Fruits: Berries, cherries apples, peaches, pears, and avocados
  • Nuts and seeds: Pecans, Brazil nuts, macadamia nuts, no-sugar-added peanut butter, pumpkin seeds, hazelnuts, and walnuts 
  • Certain fats: Olive oil, ghee, avocado oil, and coconut yogurt 
  • Herbs and spices: Turmeric, rosemary, black pepper, and mint

In addition to the foods listed above, there are plenty of Paleo-friendly products, such as baking blends, crackers, breads, and even treats like muffins and cookies that can fit into a paleo diet.

Keep in mind that Paleo-approved products are made with Paleo-friendly ingredients, such as coconut and almond flour as well as natural sweeteners like dates and monk fruit. 

What You Should Avoid Eating

When following the Paleo diet, you’ll need to cut out many commonly consumed foods and ingredients. The Paleo diet excludes some nutritious foods such as grains, legumes, and dairy products. It also restricts refined sugars, ultra-processed foods, and some oils.

Here’s a list of foods you’ll need to avoid when on the Paleo diet:

  • Grains: Wheat, barley, farro, rice, corn, oats, and rice
  • Legumes: Lentils, black beans, chickpeas, and kidney beans 
  • Dairy products: Milk, yogurt, butter, cottage cheese, and sour cream
  • Refined sugar: White sugar, agave, brown sugar, and corn syrup
  • Ultra-processed foods: Potato chips, cereal bars, candy, and other snack foods
  • Some oils: Canola oil, corn oil, soybean oil, and safflower oil
  • Artificial sweeteners: Sucralose, aspartame, and saccharin 

Keep in mind that there’s no strict set rules outlining every food and drink that should be avoided when following a Paleo diet. 

This means that some people are more restrictive than others when it comes to their food choices. While some people following a Paleo diet will eat snack foods like crackers and cookies made with Paleo ingredients, others may prefer to avoid those foods and stick to a more traditional Paleo eating pattern.

In general, you’ll want to keep your consumption of processed foods, such as snack foods like chips and sweets, to a minimum when following a Paleo diet. 

Benefits of the Paleo Diet

The Paleo diet focuses on limiting ultra-processed foods and added sugar while prioritizing whole, nutrient-dense foods known to support health, like vegetables and nuts.  

Some research findings suggest that the Paleo diet may offer a few health benefits, including lowering blood sugar levels and encouraging weight loss. 

Here are some of the ways in which following a Paleo diet may benefit health.

It May Support Healthy Blood Sugar Levels 

The Paleo diet restricts foods that may negatively impact blood sugar, such as ultra-processed snack foods and sugary beverages. People with high blood sugar levels who transition to a Paleo diet may experience reductions in their blood sugar levels. 

A 2017 study that included 32 people with type 2 diabetes found that 12 weeks of following a Paleo diet led to reductions in both short and long-term markers of blood sugar control, which were more significant when the Paleo diet was combined with one-hour supervised exercise sessions three times per week. The exercise group experienced a 1.1% reduction in the long-term marker of blood sugar control hemoglobin A1c, while the diet-only group experienced a .9% reduction.

The participants also experienced improvements in their sensitivity to insulin, a hormone that shuttles blood sugar into cells where it can be used for energy. 

A 2017 review of four studies found that Paleo diet interventions were more effective for reducing fasting blood sugar levels in participants with one or more of the five components of metabolic syndrome, a cluster of symptoms including high blood sugar levels that increases a person’s risk for developing type 2 diabetes and heart disease.  

It May Encourage Weight Loss

People often try out the Paleo diet as a way to promote fat loss. The diet is high in foods linked to a healthy body weight, like vegetables, legumes, and nuts. People following the Paleo diet may feel more satisfied after meals, which could help overeating and encourage weight loss. This is because the Paleo diet includes foods rich in fiber and protein, two nutrients that help you feel full after eating.

A 2019 review of 11 studies with intervention periods ranging from two weeks to two years found that, on average, people who followed a Paleo diet lost about 8 pounds more than those following other eating patterns.

Additionally, a 2021 study that included 32 people with type 2 diabetes found that after following the Paleo diet for 12 weeks, the participants lost an average of 15.6 pounds.

Could Reduce Heart Disease Risk Factors 

Having elevated blood pressure and blood lipid levels like LDL cholesterol and triglycerides increases your risk of developing heart disease. Some studies have found that people who follow the Paleo diet experience reductions in heart disease risk factors such as triglyceride and blood pressure levels.

In the 2021 study mentioned above, the 12-week Paleo diet intervention was associated with lower systolic blood pressure and triglycerides. Interestingly, the reduction in triglyceride levels was independent of weight loss, meaning that the composition of the diet was effective for improving blood lipid levels.

This may be because the participants decreased their intake of saturated fatty acids while increasing their intake of monounsaturated fatty acids and polyunsaturated fatty acids, both of which have beneficial effects on blood lipid levels. 

A 2022 cohort study that included information on 18,210 Spanish adults found that, during a 12-year time period, those who followed a Paleo dietary pattern were significantly less likely to develop heart disease. The researchers noted that this association was likely due to the low consumption of ultra-processed foods in Paleo dietary patterns. 

Drawbacks of the Paleo Diet

Even though the Paleo diet encourages the consumption of nutritious foods like vegetables and fruits and has been linked with some health benefits, there are some drawbacks to consider.

  • It cuts out some healthy foods: Nutritious foods such as legumes, dairy products, and whole grains are restricted on the Paleo diet. These foods are high in important nutrients such as fiber, calcium, and magnesium, which is why some experts argue that the Paleo diet is unnecessarily restrictive. 
  • It may negatively impact gut health: A small 2020 study found that people following a strict or modified Paleo diet for at least a year had lower levels of certain beneficial bacteria and greater amounts of trimethylamine (TMA)-producing Hungatella bacteria compared to those following regular diets. TMA is produced by some gut bacteria after breaking down compounds found in eggs, red meat, and dairy. TMA is turned into a compound called trimethylamine N-oxide (TMAO). Studies show that having higher levels of TMAO may increase the risk of certain diseases, like heart disease. 
  • It could cause altered bowel movements: A 2016 study that randomized 39 healthy women to either a Paleo diet or a generally healthy diet that included grains and dairy for four weeks found that women following the Paleo diet were more likely to experience constipation and irregular bowel movements compared to the unrestricted diet group.

Although a  well-planned Paleo diet that includes plenty of plant foods like fruits and vegetables can be a healthful choice, it does restrict some nutritious foods, which may not be necessary for most people. 

Paleo Diet vs Keto Diet

The keto diet is a very low-carb, high fat way of eating. It’s much more restrictive than a Paleo diet and involves significantly restricting your carb intake to less than 50 grams per day. The point of the keto diet is to reach and maintain ketosis, a metabolic state in which the body burns fat for fuel instead of sugar.

In order to reach and maintain ketosis, people following the keto diet must avoid most high-carb foods, including starchy vegetables and fruits. 

The Paleo diet is different from the keto diet in many ways. First, although it can be considered a  lower-carb diet, it doesn’t restrict all high-carb foods. It includes a variety of starchy vegetables and fruits, which are restricted on the keto diet.

Also, the Paleo diet can be adapted to suit a variety of nutrition needs and some people following the Paleo diet may include more high-carb foods than others. On the other hand, the keto diet isn’t a modifiable diet, as the purpose of the diet is to reach and maintain ketosis.

A Quick Review

The Paleo diet is a way of eating meant to resemble the diets of humans living during the Paleolithic era. It prioritizes nutritious foods like vegetables and nuts while restricting foods linked to negative health outcomes, such as ultra-processed foods and added sugars.

The Paleo diet may benefit your health in several ways, including promoting healthy blood sugar, encouraging weight loss, and reducing heart disease risk factors. However, it restricts some healthy foods, like grains and legumes, and may negatively impact your gut health.

If you’re interested in transitioning to a Paleo diet, consider working with a healthcare provider like a registered dietitian to ensure your nutritional needs are being met.

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10 Sources
Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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