In today's world, a simple internet search for the word "diet" yields over 1.5 trillion results, each claiming to be the most effective way to lose weight. Among the most popular are the paleo and ketogenic (keto) diets. Both diets attract many followers who want to lose weight or improve their overall health, but their approaches differ significantly. This article provides a detailed comparison of the paleo and keto diets to help you decide which one is best for you.
Introduction to the Paleo Diet
The paleo diet, sometimes called the "caveman diet" or "Stone Age diet," is based on the principle that eating foods available to early humans will promote optimal health. It is an eating plan modeled after the hunter-gatherer diet of early humans. This diet encourages consuming foods that our ancestors would have eaten 10,000 years ago, before modern farming methods and food processing. The fundamental theory behind the paleo diet is that modern food systems, production, and processing techniques are damaging to human health. By adjusting your eating style to mimic that of Paleolithic hunter-gatherers, you may better support your body’s natural biological function, improving digestion and health.
What You Can Eat on the Paleo Diet
The main foods permitted on the paleo diet include:
- Meat and fish (leaner cuts of meat are preferred, such as grass-fed meats)
- Eggs
- Nuts and seeds
- Fruits
- Vegetables (except corn, which is a grain)
- Selected fats and oils, such as coconut oil, olive oil, avocado oil, lard, tallow, ghee/butter
- Minimally processed sweeteners, including raw honey, maple syrup, coconut sugar, raw stevia
What You Can't Eat on the Paleo Diet
Paleo eliminates grains, legumes, processed sugar, most sources of dairy, and artificial sweeteners. The diet restricts grains, rice, and other high-carb foods. The paleo diet emphasizes consuming foods available to early humans and exercise.
Lifestyle Component
For most, paleo is more than just a diet. There is also a strong focus on lifestyle practices, the environmental impact of food choices, and total body wellness within the framework of the paleo philosophy. One of the mainstays of the paleo lifestyle is incorporating short, intense periods of exercise into your routine. This style of physical activity is thought to reduce the stress that may accompany longer workouts. When paired with the diet, these lifestyle practices are intended to support the total wellness of your body and mind, leading to better overall health.
Read also: Paleo Granola Recipes
Introduction to the Keto Diet
The keto, or ketogenic, diet aims to induce ketosis through the calculated adjustment of dietary macronutrients, namely carbs, protein, and fat. The keto diet focuses on decreasing carb intake so that your body uses fat instead of carbohydrates as its primary energy source.
What is Ketosis?
Ketosis is the metabolic state in which your body uses calories from fat, instead of carbs, to create the energy needed to carry out its normal functions. When people are eating low enough in carbohydrates, they can enter the state of ketosis. Even if they’re not eating, they can enter the state of nutritional ketosis. During periods of fasting, especially when we’re not eating anything and we’re not eating carbohydrates, our body really has to turn to an alternative fuel source, which is fat. When fat is broken down, ketones are released by fat cells into the bloodstream. The increase in blood ketones lowers the normal acid-base balance in blood to make it more acidic, a state known as ketosis.
How the Keto Diet Works
The keto diet functions by restricting carbohydrate intake to near-zero levels. A "true" keto diet does not provide enough calories from sources of glucose and other forms of sugar and causes the body to burn fat to create energy.
The keto diet macronutrient breakdown looks something like this:
- Fat: 65-90%
- Protein: 10-30%
- Carbohydrates: less than 5%
In comparison to a “standard” diet, the macronutrient distribution of the keto diet is shifted significantly in favor of fat, with moderate protein and very few carbs. The purpose of achieving ketosis with this diet plan is to induce the metabolic breakdown of fat in your body. Thus, it’s imperative that macronutrient intake is tightly controlled, as otherwise you risk throwing your metabolism out of ketosis.
Read also: Paleo Diet Delivered: What You Need to Know
What You Can Eat on the Keto Diet
That can vary depending on which keto plan somebody is following. But essentially, animal protein is very low in carbohydrates. Most fat sources are also low in carbohydrates. For this diet you’ll eat foods like fatty fish, eggs, dairy, meat, butter, oils, nuts and seeds, and low-carb vegetables. High-fat dairy in the form of heavy cream, butter, and unsweetened full-fat yogurt are mainstays of many ketogenic diet plans. Soy foods like tofu, tempeh, and soybeans are allowed on the keto diet as long as they fall within your specified macronutrient allotment.
What You Can't Eat on the Keto Diet
Avoid anything that is really high in carbohydrates, such as simple sugars, processed sugars, juice, starches, breads, potatoes, corn, rice. Fruits that are higher in sugar include tropical fruits, such as pineapple, grapes, bananas, mangoes, papaya. Other dairy products, like ice cream or milk, are prohibited on the keto diet but this is mostly due to their low fat-to-carb ratio. Soy milk, however, is usually discouraged. Conversely, the keto diet restricts all rich sources of carbohydrates, including starchy vegetables, most fruits, grains, sweeteners, and most legumes. Due to the fact that total carb intake must remain below a certain threshold to maintain ketosis, many high-carb foods, regardless of their source, simply don’t fit into a keto diet.
Phases of the Keto Diet
- Phase 1 (Induction): Consume under 20 grams of carbs per day for two weeks. Focus on high-fat, high-protein foods, with low-carb vegetables like leafy greens.
- Phase 2 (Balancing)
- Phase 3 (Fine-tuning)
- Phase 4 (Maintenance)
Similarities Between the Paleo and Keto Diets
Although they are distinct, paleo and keto diets share many characteristics. Below are some of the main ideas these diets have in common.
Emphasis on Whole Foods
Fundamentally, both paleo and keto diet plans are intended to rely on whole-food sources of nutrients. A whole food is a food that has undergone a minimal amount of processing by the time it gets to your plate. Both keto and paleo diets strongly encourage eliminating all ultra-processed foods and replacing them with whole foods like fresh vegetables, meat, fish, and nuts. This is especially evident with the exclusion of processed fats, oils, and sweeteners in both paleo and keto “rule books.”
Elimination of Grains and Legumes
Though for different reasons, both paleo and keto diets strongly discourage eating grains and legumes. For the paleo crowd, this elimination is largely based on the fact that grains and legumes were not likely part of early human diets and they contain antinutrients. Antinutrients are compounds, such as lectins and phytates, that can be found in some plant-based foods. They interfere with your body’s ability to absorb minerals and nutrients and may cause digestive distress when eaten in large quantities. On the other hand, research suggests that there may also be benefits to eating foods with these compounds. The keto diet also eliminates grains and most legumes, but this is because of their carbohydrate content. Grains and legumes contribute a significant amount of carbs to the diet. If you eat them while following the keto diet, you risk throwing your body out of ketosis.
Read also: Paleo Mayonnaise Recipe
Elimination of Added Sugar
Keto and paleo diets strongly discourage the intake of added sugars. For both diet plans, this largely falls under their shared message of avoiding heavily processed foods in general. However, paleo dieters are a bit more flexible with this rule, as unrefined sugar sources like honey and maple syrup are still permitted. Keto, on the other hand, doesn’t allow any added sugar sources, refined or not, due to the high carb content of these foods.
Emphasis on Healthy Fats
In line with their shared goal of achieving optimal health, both paleo and keto diets encourage the intake of unrefined, healthy fats. Both diets also recommend moderate-to-liberal amounts of selected refined oils, such as olive and avocado oils, as well as nuts, seeds, and fish. These foods are known to benefit heart health because of their poly- and monounsaturated fat content. Both diets also discourage the use of heavily processed fats, such as trans fats, which are detrimental to health when consumed regularly. Keto places very heavy emphasis on fat in general, as it is the cornerstone of the entire diet. Paleo, while not necessarily a high-fat diet, uses this recommendation to support overall health.
Potential for Weight Loss
One of the primary reasons for the popularity of keto and paleo diets is the notion that they will promote weight loss. Weight loss is a benefit of both keto plans and paleo plans. Any diet that’s limiting calories and is easy to stick to can help people lose weight. Unfortunately, there is limited research available for how effective these diets are for sustained, long-term weight loss. However, some short-term research is promising. A small study of postmenopausal, obese women following the paleo diet showed a 9% weight loss after six months and a 10.6% loss at 12 months. No additional significant change in weight was seen at the 24-month mark. One review of research on low-carb, high-fat (LCHF) diets, such as the ketogenic diet, indicated that short-term weight loss can occur when switching to this style of eating. This may have been because a high intake of fat usually leads to a decrease in appetite and fewer overall calories consumed. It may also be that the process of ketosis is leading to more efficient elimination of the body’s fat stores. The exact reason is still unclear. Ultimately, more research is needed to determine a clear causal relationship.
Key Differences Between the Paleo and Keto Diets
One of the key differences between the paleo and keto diets is the ideological message, or lack thereof. The paleo diet places a heavy emphasis on lifestyle choices beyond just the diet. It explicitly encourages a specific style of exercise and mindfulness in daily activities to accompany the dietary pattern. While the paleo diet regimen is very specific, it doesn’t place any emphasis on macronutrients at all. You are permitted to eat as much protein, fat, and carbohydrates as you want, provided you’ve chosen them from the set list of “allowable” foods. Keto, on the other hand, doesn’t have an associated ideology or lifestyle component. While it does encourage choosing healthy food sources, the main focus is macronutrient distribution. Any other implemented lifestyle changes alongside the keto diet are up to the individual and are not part of the diet regimen itself.
Carbohydrate Intake
Although paleo does restrict some carb sources, it isn’t necessarily a low-carb diet in the same way keto is. Because paleo does not emphasize macronutrients, your diet could theoretically be very high in carbs, depending on which foods you choose to eat within the specified parameters. Because grains, refined sugars, and legumes aren’t permitted, the carb sources on the paleo diet are somewhat limited but not eliminated. Paleo still allows carbs from groups of whole foods such as fruits, vegetables, and unrefined sweeteners. Conversely, the keto diet restricts all rich sources of carbohydrates, including starchy vegetables, most fruits, grains, sweeteners, and most legumes. Due to the fact that total carb intake must remain below a certain threshold to maintain ketosis, many high-carb foods, regardless of their source, simply don’t fit into a keto diet.
Dairy and Soy
Keto permits, even encourages, eating many dairy foods. High-fat dairy in the form of heavy cream, butter, and unsweetened full-fat yogurt are mainstays of many ketogenic diet plans. Other dairy products, like ice cream or milk, are prohibited on the keto diet but this is mostly due to their low fat-to-carb ratio. Soy foods like tofu, tempeh, and soybeans are allowed on the keto diet as long as they fall within your specified macronutrient allotment. Soy milk, however, is usually discouraged. Paleo, on the other hand, doesn’t allow for any soy and restricts almost all dairy. Grass-fed butter is the one permitted dairy product on the paleo diet. However, there is some disagreement within the paleo community about whether or not this allowance is truly in line with the paleo ideology. Additionally, paleo does not allow for any soy products because they fall into the legume category of foods.
Health Benefits of Paleo and Keto Diets
When people lose weight, their general health and well being improve. They lower their risk of cancer, high blood pressure, heart disease, diabetes, depression, sleep apnea and dementia.
Paleo Diet Benefits
Benefits of trying the paleo diet include:
- Eating less processed foods: The biggest selling point of the paleo diet is its insistence on cutting out processed foods. There are negative health effects linked to eating these foods.
- Weight loss: One of the main benefits of the paleo diet is fast weight loss. Studies have shown that by following this plan you’re likely to see a body mass index (BMI) decrease and a waist size reduction.
- Cardiovascular health: Some studies have shown that the paleo diet lowers your risk of cardiovascular disease. Since the paleo diet helps you lose weight and decrease BMI, your blood pressure and total cholesterol levels are reduced.
- Blood sugar regulation: Restricting dairy, refined sugar, and carbohydrates from your diet can help regulate your blood sugar and reduce your risk of type 2 diabetes.
Keto Diet Benefits
Benefits of the keto diet include:
- Weight loss: On the keto diet, you’ll be eating foods high in fat. These types of food make you feel full for longer. There are weight loss effects when you are in ketosis - a state in which your body uses stored fat for energy instead of blood sugar.
- Effects on certain conditions: If you have epilepsy or another neurological disorder, your doctor might prescribe the keto diet. Studies have shown that the keto diet can reduce seizures. There are also emerging studies that show benefits for people with Parkinson’s disease.
Risks and Considerations
Like most diets, there are some things you should watch out for when trying the paleo diet.
- High cost: Buying whole foods can be much costlier than their processed counterparts that have been frozen or canned.
- Nutrient deficiencies: Cutting out all grains and legumes leaves you without enough B vitamins like thiamine, folate, niacin, and riboflavin. You might be most at risk for not getting enough calcium or vitamin D.
- High meat intake: The paleo diet requires you to eat more meat. Studies have linked eating more red meat to health risks. These risks include cardiovascular disease, diabetes, and an increased risk of death.
Some of the potential cons of the keto diet include:
- Not enough nutrients: Like the paleo diet, you’re cutting out specific foods. By eliminating grains and most fruits, you may not get enough selenium, magnesium, phosphorus, and vitamins B and C.
- Liver and kidney problems: Metabolizing the fat in this diet can be hard on your liver. The level of protein can be difficult for your kidneys to metabolize. If you already have liver or kidney problems, this diet can make them worse.
- Fuzziness and unclear thoughts: Your brain uses healthy carbohydrates to function. If it doesn’t get the amount it needs to function well, you may feel confused or irritable.
- Potential rise in LDL (bad) cholesterol: The downside, even for the short term, is a potential rise in LDL (bad) cholesterol.
The keto diet is not recommended for people with:
- Pancreatic disease
- Thyroid problems
- Eating disorders or a previous eating disorder
- Gallbladder disease, or who have had their gallbladder removed
- Advanced kidney problems
- Women who are pregnant or who are nursing
Also, people should generally avoid eating too much saturated fat on a high-fat diet. Studies suggest it may increase the risk of heart disease.
Which Diet is Right for You?
Both paleo and keto diets can be healthy options, depending on how they are implemented and what they are used for. Any type of eating plan really depends on your personal preferences, what you enjoy eating, what you think you could continue in the long run because it shouldn’t be a temporary fix. The data has shown that short-term diets usually fail in the long-term because people will regress to their prior eating habits. When deciding on the best diet for you, think about what’s sustainable. You should talk to your doctor or nutritionist about the right diet plan for you.
- Paleo: In a side-by-side comparison, the paleo diet is a healthier option for most people. Paleo allows for more flexibility of food choices and more options for obtaining the wide array of nutrients your body needs on a daily basis. It also encourages an overall healthy lifestyle. Freedom within food choices makes paleo easier to maintain long-term with less potential to be socially isolating.
- Keto: Keto does not suit everyone and may be beneficial as a treatment method for some health conditions. Keto is more difficult to maintain because of the strict compliance needed to achieve ketosis. It requires careful planning and can be less adaptable to varied social situations. Keto’s lack of flexibility can also make getting adequate nutrients a challenge because of the limited options.
A good candidate for a keto eating plan is somebody who is very motivated, enjoys the food in the plan, and wants to do it forever because really, it’s a long-term solution and not a short-term plan. A good candidate for a paleo plan is somebody who enjoys the foods in the plan, wants to continue it indefinitely or for at least the majority of the time.