The keto and paleo diets are among the most popular diets today. They share some similarities, but there are also differences in the foods they allow, their effects on the body, and key health effects.
The ketogenic (keto) diet focuses on eating a particular balance of macronutrients. The goal is to enter a state of ketosis, where the body begins to burn fat for health or weight loss.
The Paleolithic (paleo) diet focuses on eating foods that humans would have eaten in the Stone Age. The goal is to eliminate modern processed foods for health or weight loss.
This article looks at the similarities and differences between the keto and paleo diets, including their benefits, food lists, and side effects.
The keto and paleo diets are two dietary options that aim to boost health, eliminate highly processed foods, and encourage weight loss.
The following sections provide an overview of keto and paleo diets:
A keto diet is an eating plan that focuses on eating lots of healthful fat, some protein, and minimal carbohydrates.
The body typically uses carbohydrates as fuel for energy. When a person does not get enough carbs, the body will start using up fat and some protein stores. In true ketosis, the liver will take stored fat and turn it into ketones, which the body then uses for energy. Reaching this state of ketosis is the goal of the keto diet.
In general, a person on a keto diet should consume:
- 70–80% fat
- 20–25% protein
- 5–10% carbohydrates
The keto diet encourages and excludes specific foods. A person on keto cannot get their carbohydrates from grains or legumes. Their carbs must come from a keto friendly vegetable, such as leafy greens, or a small group of fruits, primarily berries.
A paleo diet is a dietary plan that focuses on foods that humans ate during the Paleolithic era. Some people refer to it as the caveman diet or the Stone Age diet.
This diet strives to eliminate products made via modern food processing and farming methods. People who follow the paleo diet may choose foods that a Stone Age ancestor would have been able to hunt or gather and eat. The diet of a Stone Age person would have varied according to the natural resources available in their area.
Some people believe that the human body is not well adapted to modern-day foods. According to supporters of the diet, cutting out foods such as dairy, grains, and legumes can help a person lose weight and prevent heart disease and diabetes.
A paleo diet excludes highly processed foods, as well as legumes, grains, and dairy products.
The paleo diet also encourages the consumption of healthful fats, such as those from wild or grass-fed animals, nut oils, butter, olive oil, and avocados. It also recommends that people eat higher amounts of animal protein.
According to some small, short term studies, the paleo diet may have benefits for metabolic syndrome and improving cholesterol levels. However, scientists need to carry out more research to confirm this.
Both diets encourage the consumption of many nutritious whole foods and exclude highly processed foods.
Both involve a low carb intake and do not allow the consumption of grains and legumes. They emphasize meat for protein and recommend certain types of fats and vegetables.
Both paleo and keto diets include:
- unprocessed meat
- healthful fats, such as olive oil, avocado oil, and nut oils
- non-starchy vegetables
Exclusion of highly processed foods
Both keto and paleo diets exclude many unhealthful foods, including:
- processed foods, such as chips, crackers, and packaged snacks
- foods that contain white or brown sugar, corn syrup, or agave nectar
Exclusion of healthful foods
Both diets exclude a variety of foods that many people would consider healthful. In fact, the 2015-2020 Dietary Guidelines for Americans lists some of these foods.
- whole grains, including rice, wheat, quinoa, pasta, bread, and oats
- legumes, including beans, peanuts, peas, soy, and lentils
These two diets encourage lower carbohydrate intake than the traditional reduced calorie or low fat weight loss plans that experts have recommended for years. For instance, the National Institutes of Health (NIH) and American Heart Association recommend a daily intake of whole grains, which are not a part of keto and paleo plans.
The keto and paleo diets exclude different foods. The keto diet excludes high sugar foods, including most fruits, while the paleo diet allows more fruits and some natural sweeteners. They also have different rules for meats, vegetables, and dairy.
The following sections look into key differences between the keto and paleo diets.
A paleo diet usually excludes processed meats, such as bacon, salami, and ham, as these are the result of modern food processing techniques. Some people believe that minimally processed bacon without nitrates or preservatives is acceptable on the paleo diet, while others do not.
The keto diet allows these types of meat as long as they do not contain sugar or carbohydrates, which could interfere with the body’s ability to reach ketosis. Some processed meats, such as bacon or sausage, may contain sugar, so people need to read the labels.
However, with research indicating that processed meats may increase the risk of cancer and other health issues, people on any diet may wish to focus on eating good quality meats rather than processed ones.
- Paleo: Focuses on natural and grass-fed, no processed meat.
- Keto: Allows any meat that does not contain added sugar or carbohydrates.
Sweeteners and sugar
The paleo diet allows some “natural” sweeteners, such as honey and maple syrup. But, it does not allow artificial sweetener, including sugar alcohols, because they are a result of modern technology.
The keto diet allows some artificial sweeteners as long as they do not contain any sugar (some products contain both sugar and artificial sweeteners). Ideally, a person should choose sweeteners that do not cause spikes in blood sugar, such as stevia and sucralose.
The keto diet does not allow honey, maple syrup, or other products that contain natural sugar or fructose.
- Paleo: Allows raw honey, maple syrup, date sugar, and coconut sugar.
- Keto: Does not allow any sugars, but allows some artificial sweeteners, such as stevia and sucralose.
Some nutrient rich vegetables also have a high starch or carbohydrate content. These “starchy vegetables” are not allowed on the keto diet because they could interrupt ketosis and cause a person to consume more than their allotted total of carbohydrates.
However, the paleo diet allows many of these nutritious vegetables in moderation. A person following the paleo diet can eat foods such as sweet potatoes, beets, and carrots in moderation, but should prioritize lower carb vegetables.
Fruits contain a range of nutrients, vitamins, minerals, fiber, and antioxidants, and are a healthful choice for most people. However, fruits also contain some natural sugar, and some have higher levels of sugar and carbohydrates than others.
A person following a paleo diet can eat all fruits, including fresh, dried, and frozen, but they should generally focus on lower sugar types. A paleo diet includes plenty of berries, citrus fruits, and melons. It can include sweeter fruits, such as bananas, grapes, mangoes, and cherries, but ideally, in lower amounts.
The keto diet is more strict with fruit. It advises that to keep the body in a state of ketosis, a person should only eat lower sugar fruits, and only in small amounts. Berries are a common keto friendly fruit, but a person may also eat small amounts of cranberries, peaches, apricots, apples, and plums.
- Paleo: Allows all fruits, though higher sugar ones in moderation.
- Keto: Allows only lower sugar fruits.
The paleo diet excludes all dairy products because Paleolithic humans did not consume them. The paleo diet does not allow a person to consume cheese, milk, cream, or other dairy products.
However, people on the paleo diet can drink unsweetened nut milk, coconut milk, and similar alternatives that do not contain artificial sweeteners or thickeners.
The keto diet allows some dairy products, especially those that are higher in fat and protein. This allows the person to take in the recommended amounts of these nutrients.
The keto diet does not include any dairy products that may contain sugar, such as ice cream, chocolate milk, or sugar-sweetened coffee creamer. However, a person may consume dairy products that contain artificial sweeteners in moderation.
- Paleo: Excludes dairy products.
- Keto: Allows dairy without sugar, ideally higher fat and higher protein types.
People following any diet that eliminates food groups should make sure they are meeting their daily nutrient requirements to avoid deficiencies.
Anyone considering making a new and drastic change to their eating pattern should check in with their healthcare provider first. This is especially important for people who have chronic health conditions, such as heart disease, diabetes, or high blood pressure.
People following the keto diet may experience side effects related to entering a state of ketosis. These include keto breath, a keto skin rash, and the “keto flu.” Symptoms off the keto flu include headaches, lethargy, nausea, mental slowness, insomnia, decreased exercise performance, constipation, and low libido. It can be harmful to stay in a state of ketosis for extended periods.
People do not experience these symptoms with paleo diets, as paleo diets do not lead to a state of ketosis.
Certain nutritional supplements can help people following the keto diet to get enough nutrients, ease side effects, and meet their daily macronutrient goals. Read about 7 supplements for the keto diet here.
One article cautions people who follow the paleo diet to make sure they are getting adequate calcium since the diet excludes dairy products. The keto diet lacks fiber and several micronutrients due to the severe restriction of foods that contain carbohydrates.
The following sections provide a list of foods that a person can eat when following the keto or paleo diet.
Common foods that people eat when following the keto diet include:
- fatty fish, such as salmon, tuna, or sardines
- shellfish, including mussels, clams, or oysters
- fatty cuts of meat
- game meat
- non-starchy vegetables, such as leafy greens, cruciferous vegetables, asparagus, olives, bell peppers, celery, and squash
- plain Greek yogurt with no sugar or fruit
- plain cottage cheese
- eggs, especially egg yolks
- healthful oils, such as olive oil, nut oils, and avocado oil
- nuts, including macadamia nuts, pistachios, peanuts, walnuts, and almonds
- seeds, including chia seeds and flaxseed
- butter, ghee, or cream
- coconut or cocoa butter
- dark chocolate with at least 70% cocoa solids and very little to no sugar added
- nut butters, including almond butter, that contain no added sugar
- berries, including raspberries, blueberries, strawberries, and blackberries
- lemons and limes
- bone broth
- unsweetened tea and coffee
Common foods that people eat when following the paleo diet include:
- game meat
- vegetables, especially leafy greens, celery, asparagus, peppers, and cruciferous vegetables
- small-to-moderate amounts of starchy vegetables, such as potatoes and root vegetables
- fruit, emphasizing berries, tomatoes, citrus, and other lower sugar fruits
- small or moderate amounts of higher sugar fruits, such as grapes and bananas
- nut butter
- cocoa butter
- dark chocolate with at least 70% cocoa
- coffee with no dairy cream or refined sugar
- healthful oils, including nut oils, olive oil, and avocado oil
- honey, maple syrup, and coconut sugar in small amounts
Both the keto and paleo diets have specific guidelines that include and exclude certain types of food. There are some similarities but plenty of variation between the diets. Both may have health benefits related to eliminating highly processed foods, which may help with weight loss.
For most people, these diets require a drastic shift from previous eating habits. Some people may find eliminating all grains and legumes and increasing fat content difficult to sustain long term. People following these diets must also make sure they still meet their nutritional requirements.
A person should base their decision to follow either of these diets on their current health condition, how strict they want to be with their diet, and their individual health goals.
Some people following the paleo diet will eat processed foods as long as they are low sugar, contain no dairy or grains, and are paleo friendly. Others on the paleo diet may eat only foods in their natural state, excluding anything that comes in a package. Some people on the keto diet eat any meat, as long as it is carb free. Others focus on grass-fed and healthful meats only.
People will benefit from speaking with their doctor before changing their diet, especially if they have diabetes, heart disease, or other health conditions.