What can you not eat on a paleo diet? A guide to excluded foods

December 21, 2025 •

4 min read

Based on the diet of ancient hunter-gatherers, the paleo diet excludes certain modern food groups. So, what can you not eat on a paleo diet? The plan focuses on eliminating foods that became common with the advent of farming, such as grains and dairy.

Quick Summary

The paleo diet removes grains, legumes, dairy, and refined products from the diet, focusing instead on whole foods available to our ancestors. This guide details the specific food groups and items to exclude and the rationale for these restrictions.

Key Points

Grains are excluded: The paleo diet prohibits all cereal grains like wheat, rice, and oats, based on the belief they are not well-adapted to the human body.
Legumes are not allowed: Beans, lentils, and peanuts are considered off-limits due to 'anti-nutrients' like lectins and phytic acid.
Dairy is removed: Strict paleo eliminates all dairy products, as ancient hunter-gatherers did not consume them.
Processed foods are forbidden: Anything highly processed, including refined sugars, excessive salt, and many unhealthy vegetable oils, should be avoided.
Focus on whole foods: The core of the paleo diet is consuming whole, unprocessed foods like meat, fish, fruits, and vegetables.
Potential nutrient gaps: The diet can lead to deficiencies in nutrients like calcium and fiber if followers don't consciously incorporate alternative sources.

The paleo diet, often called the “caveman diet,” is based on the eating habits of our Paleolithic ancestors before the rise of agriculture approximately 10,000 years ago. The core philosophy is that the human body is not optimally adapted to digest foods introduced by modern farming and food processing. To follow this way of eating, it's essential to understand the specific categories and ingredients that must be avoided. By eliminating these items, proponents aim to reduce inflammation and improve overall health.

The Core Exclusions: What to Avoid on Paleo

Grains: No Bread, Pasta, or Cereal

Grains are one of the most significant food groups excluded from a standard paleo diet. This includes a wide array of staple modern foods derived from grains.

Commonly excluded grains include:

Wheat, rye, and barley (including flour-based products like bread and pasta)
Oats
Rice (some versions make an exception for white rice)
Corn
Quinoa and buckwheat (pseudograins, but still avoided by strict followers)

The main rationale for avoiding grains is that they contain “anti-nutrients” like phytates and lectins, which are thought to interfere with nutrient absorption and contribute to inflammation.

Legumes: Off-Limits Beans, Lentils, and Peanuts

Another major food group to avoid is legumes, which are seeds, pods, or beans that are high in fiber, protein, and various micronutrients. Like grains, legumes were not part of the ancestral hunter-gatherer diet and are a product of agricultural development.

Commonly excluded legumes include:

Beans (black, pinto, kidney, etc.)
Lentils
Peanuts and peanut butter (peanuts are technically legumes, not nuts)
Soy products (tofu, edamame, soy milk)
Peas (including snow peas and snap peas)

The exclusion is based on the presence of lectins and phytic acid, similar to the reasoning for avoiding grains. Some individuals find that consuming legumes causes digestive issues.

Dairy: A Modern Addition to the Diet

Since humans did not milk other animals during the Paleolithic era, all dairy products are excluded from a strict paleo diet.

Commonly excluded dairy products include:

Milk (cow, goat, sheep)
Cheese
Yogurt
Butter (some versions, especially the Primal diet, allow grass-fed butter or ghee)
Ice cream
Kefir

The paleo community cites issues with lactose (milk sugar) and casein (milk protein) as potential sources of digestive problems and inflammation for many people. Eliminating dairy can also pose a risk for calcium deficiency if not properly managed with other calcium-rich foods like leafy greens.

Processed Foods and Refined Sugars: The Factory-Made Problem

Perhaps the easiest rule to remember is to avoid anything that is highly processed or contains refined ingredients. This principle cuts out a huge portion of the modern Western diet.

Examples of processed items to avoid:

Sugary soft drinks, fruit juices with added sugar
Candy, cookies, and other pastries
Chips, crackers, and other salty snacks
Most fast food and convenience meals
Refined table sugar and high-fructose corn syrup

Unhealthy Fats: Specific Oils to Avoid

While healthy fats are encouraged on paleo, certain highly processed vegetable oils and trans fats should be excluded.

Fats to avoid include:

Soybean oil
Corn oil
Canola oil
Margarine
Shortening (often contains hydrogenated or trans fats)

Paleo vs. Modern Diet: A Comparative Look


Food Group	Paleo Diet	Modern Western Diet
Grains	Excluded completely (wheat, rice, oats)	Often a staple (bread, pasta, cereal)
Legumes	Excluded completely (beans, lentils, peanuts)	Common source of fiber and protein
Dairy	Excluded completely by strict followers	Common source of calcium, protein, and fat
Processed Foods	Excluded; emphasis on whole, unprocessed foods	Heavily reliant on pre-packaged and convenience foods
Refined Sugar	Excluded; natural sweeteners used in moderation	High consumption through sweets, drinks, etc.
Healthy Fats	Emphasizes natural fats (nuts, seeds, avocado, olive oil)	Can include unhealthy trans fats and vegetable oils
Salt	Low intake, from natural foods only	High intake from processed foods

Navigating a Paleo-Friendly Lifestyle

Adopting a paleo diet requires intentional choices, especially for those accustomed to a modern, processed diet. Learning to read food labels becomes crucial to identify hidden sugars, grains, or undesirable oils. The good news is that the diet's focus on whole, unprocessed foods can lead to better health outcomes, such as weight management and reduced blood sugar. However, it's important to be mindful of potential nutritional gaps caused by eliminating major food groups. Consulting with a healthcare provider or a registered dietitian is always recommended before making significant dietary changes. For more information on the diet's rationale and practical considerations, the Mayo Clinic offers a detailed overview of the paleo diet. Paleo diet: What is it and why is it so popular?

Conclusion

Ultimately, knowing what can you not eat on a paleo diet is the key to success. The most fundamental exclusions are grains, legumes, dairy products, processed foods, and refined sugars. These restrictions are based on the historical premise that our bodies have not fully adapted to these agricultural-era foods. By focusing on meats, fish, vegetables, fruits, nuts, and seeds, followers aim to nourish their bodies with whole, natural ingredients. While the diet requires careful planning, especially to ensure adequate nutrient intake from alternative sources, it offers a clear framework for healthier eating.

Frequently Asked Questions

No, a strict paleo diet excludes all dairy products, including cheese, because they were not available to humans during the Paleolithic era. Some modern, more flexible versions of the diet may make an exception for high-quality, grass-fed dairy like butter or ghee.

Grains are excluded because they were introduced to the human diet only after the agricultural revolution. Proponents argue they contain anti-nutrients like phytates and lectins, which can impair nutrient absorption and cause digestive issues.

Legumes are not part of the paleo diet for reasons similar to grains—they contain lectins and were not traditionally consumed by hunter-gatherer ancestors. This includes all types of beans, lentils, and even peanuts.

While some strict versions exclude white potatoes due to their high glycemic index, many modern interpretations allow them. The diet generally encourages starchy vegetables like sweet potatoes and other root vegetables as a source of carbohydrates.

You should avoid highly processed vegetable oils such as soybean, corn, canola, and cottonseed oil. Trans fats and margarine are also strictly prohibited. Instead, opt for natural, less-processed fats like olive oil, avocado oil, and coconut oil.

Refined sugars and high-fructose corn syrup are strictly forbidden. While natural sweeteners like honey or maple syrup are sometimes used in moderation, the goal is to significantly reduce sugar intake overall.

Instead of grain-based bread or pasta, people on a paleo diet use vegetables like zucchini noodles, cauliflower rice, or sweet potato toast. There are also many recipes for breads and other baked goods made with grain-free flours, such as almond or coconut flour.