Healthy Diets: Comparing Paleo, Keto and Mediterranean

By Dr. Samer Koutoubi, M.D., Ph.D.
Department Chair and Faculty Member, Public Health

Out of all the healthy diets currently in existence, which diet should you follow for healthy eating and weight loss? Which diet is the right one for your body? 

Paleo, Keto and Mediterranean diets are all very popular. Each of these healthy diets follows a different style and path, but they are largely based on healthy foods and quality macronutrients (healthy fats, high-quality proteins, complex carbohydrates, and high amounts of vegetables and fiber).

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What Do Healthy Diets Involve?

According to the Cambridge Dictionary, a traditional diet includes the food and drink usually eaten or drunk by a person or group. A diet can also involve a limitation on the food that you eat or an eating plan in which you eat less food or only particular types of food. Healthy diets may be used to lose weight, keep a medical condition under control or maintain overall physical fitness.

According to the Centers for Disease Control and Prevention (CDC), achieving and maintaining a healthy weight includes healthy eating, physical activity, optimal sleep, and stress reduction. The CDC also notes that other factors – such as genetics and certain diseases – may also affect weight loss.

Fad diets may promise fast weight loss results, but such diets limit your nutritional intake, can involve unhealthy foods and tend to fail in the long run. According to the United States Department of Agriculture’s Dietary Guidelines for Americans 2020–2025, a healthy eating plan:

• Emphasizes fruits, vegetables, whole grains, and fat-free/low-fat milk and milk products
• Includes a variety of protein foods such as seafood, lean meats, eggs, legumes (beans and peas), soy products, nuts, and seeds
• Is low in added sugars, sodium, saturated fats, trans fats and cholesterol
• Stays within your daily calorie needs

What Are the Paleo, Keto and Mediterranean Diets?

The Paleo diet is one of the most popular diets and is designed to mimic the type of diet consumed by our hunter-gatherer ancestors over 10,000 years ago. According to the Mayo Clinic, the purposes of the Paleo diet are to lose weight, maintain a healthy weight and reduce chronic diseases such as cardiovascular disease.

According to Epilepsia, the Keto (ketogenic) diet started in the 1920s as a treatment for epilepsy. It consisted of consuming high-fat foods that would provide as much as 80-90% of daily calories, a moderate amount of protein (10-20%), and low-carbohydrate foods (5%) to treat patients with epilepsy.  

The main principle involved in the Keto diet is for your body to use fatty acids and ketone bodies as the main sources of energy, instead of carbohydrates (glucose). This process is called ketosis, which is where the name of the diet comes from.

According to Medical News Today, the purpose of using the Keto diet is to support weight loss, reduce the risk of certain cancers and improve acne. This diet can also help to improve heart health, reduce seizures and improve polycystic ovary syndrome (PCOS) symptoms.

The Mediterranean diet is inspired by the traditional foods that people eat in countries located near the Mediterranean Sea, including France, Spain, Greece and Italy. The Gerontological Society of America notes that the purpose of using the Mediterranean diet is to promote weight loss, improve heart health, and prevent heart attacks, stroke, and Type 2 diabetes.

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What Can You Eat on the Paleo, Keto and Mediterranean Diets?

All three healthy diets – Paleo, Keto and Mediterranean – involve different types of foods. According to Healthline, the Paleo diet includes typical hunter-gatherer food such as grass-fed meat, chicken, eggs, fish, vegetables, fruits, seeds and nuts. The Paleo diet focuses more on pasture-fed animals that are raised under a controlled environment.

For the Keto diet, Healthline notes that this diet involves meat, fish, eggs, butter, high-fat cheeses, nuts, seeds, heavy creams, oil, avocados, and green, leafy vegetables. Other foods that are low in carbohydrates are also permitted.

The Mediterranean diet focuses more on plant-based and fresh foods. It includes fresh fruits and vegetables, fresh fish and chicken, whole grains, legumes (beans, peas, lentils, and chickpeas), nuts, extra-virgin olive oil, and a lot of herbs and spices. On this diet, there is a limited amount of eggs and dairy foods such as yogurt and cheeses.

What Should You Not Eat on Healthy Diets such as the Paleo, Keto and Mediterranean Diets?

All three of these healthy diets also involve staying away from certain foods. For instance, people on the Paleo diet should avoid:

• All refined sugar and added sugar in their foods
• Dairy products such as milk, cheese, yogurt and butter
• Legumes such as beans, peanuts, lentils, peas, soybeans and soy products
• Grains such as corn, oats, barley, wheat and rice
• Starchy vegetables like potatoes and yams
• Salty foods
• Packaged or processed foods such as chips and cookies
• Processed meat like deli meats, hot dogs and sausages

People on the Keto diet should limit their intake of alcohol and avoid:

• High-carbohydrate foods such as bread, sweets, pasta, rice and grains
• Starchy vegetables like potatoes and sweet potatoes, corn and beans
• Fruit

People on the Mediterranean diet should avoid:

• All packaged and processed food such as fast food, popcorn and ready-to-eat meals
• Foods with added sugar
• Refined grains such as bread, pasta, chips and crackers
• Processed meat such as deli meats, hot dogs and sausages
• Refined oils such as canola, soybean and cottonseed oils

Pros and Cons of the Paleo, Keto and Mediterranean Diets

Each one of these healthy diets has its pros and cons. For instance:

• The Mediterranean diet emphasizes foods and general eating guidelines, rather than numbers and calories. By contrast, the Keto and Paleo diets are very restrictive and involve a lot of numbers and calorie counting (grams of macronutrients).
• The Mediterranean diet involves nutrient-rich food groups such as whole grains, legumes, and other fiber-rich carbohydrate foods. The Keto diet does not emphasize these nutrient-rich food groups.
• The focus of the Keto diet is on eating a high-fat diet for a long period of time, which may be unsustainable and lead to many negative health consequences such as a high cholesterol level. Also, stopping the Keto diet may lead to weight gain.
• The Mediterranean and Paleo diets use more fruits and vegetables than the Keto diet. The Mediterranean diet emphasizes plant-based, fresh foods that can be consumed anytime, and it is a more sustainable type of diet.
• The Mediterranean diet involves the inclusion of healthy fats such as olive oil, avocados, whole grains, legumes and leafy greens. By contrast, the Keto diet emphasizes the consumption of very high-fat foods (like cheese, bacon, and butter), a moderate amount of protein, and other very low-carbohydrate foods.

There are significant health risks associated with all three diets. For instance, the Keto diet may lead to high cholesterol, low blood pressure, hypoglycemia, and kidney stones, according to Healthline, the University of Chicago, Livestrong, and Everyday Health.

Consuming the foods of a Paleo diet can lead to high cholesterol, low blood pressure, and hypoglycemia, according to WebMD, Healthline, and Diabetes.co.uk. The Mediterranean diet leads to lower cholesterol and stable blood sugar, according to Medline Plus.

Ultimately, lifestyle modifications including healthy diets, regular exercise and stress reduction are a must to reduce your risk factors for chronic diseases. Following the right diet program and allowing sufficient time to see results are crucial for success. If you have or are at risk for developing chronic diseases, it is crucial to discuss your options with your healthcare team, including a physician, dietitian, or nutritionist.

About the Author

Dr. Samer Koutoubi is the Department Chair of Public Health. He earned his Ph.D. in Dietetics and Nutrition from Florida International University in 2001. Dr. Koutoubi earned his M.D. degree in 1988 from Iuliu Hațieganu University of Medicine and Pharmacy in Cluj-Napoca, Romania. His research focuses on coronary heart disease among tri-ethnic groups, including African-Americans, Caucasians and Hispanics. His interest is in disease prevention and wellness, epidemiological research, cardiovascular disease and nutrition, homocysteine metabolism, lipoprotein metabolism, and cultural food and health.

Dr. Koutoubi has also authored several articles in peer-reviewed journals and wrote a book review. He served as the Editor-in-Chief for The Internet Journal of Alternative Medicine and reviewed manuscripts for The Journal of Alternative and Complementary Medicine, Ethnicity and Disease Journal, European Journal of Clinical Nutrition, and The Journal of The National Medical Association. Dr. Koutoubi has also been quoted in national magazines and newspapers, including Natural Health Magazine, Energy Time, Well Being Journal, Northwest Prime Time, and Natural Food Merchandiser.