• Livia Ly, MS, RD, LDN

Popular Diets - Paleo vs Ketogenic

Updated: Feb 24, 2019


There are so many fad diets out there that are here today and gone tomorrow. Looking at the diet timeline of over the past decades, can you believe that there was a time of cookie diets, cabbage soup diets, and even a cigarette diet?

Since the 1800s there have been hundreds of popularized diets and looking back it seems obvious which ones are just ridiculous, harmful, and not healthy. It is important to know all the facts before diving into today’s popular diets.

Today you will learn about the good and the bad on two popular diets:

Paleo and Ketogenic 



The Paleo Diet   is one of the largest popularized diets of this decade. Commercial Paleo cookbooks began to pop up in stores around 2010 and the diet has since grown in popularity with the expansion of Paleo food products, literature, and a large following of dedicated dieters. This diet is known as the Paleolithic diet, Caveman diet, Hunter-Gatherer diet, and Primal diet.

The food selection is based on what our ancient, primal ancestors would have eaten before the agricultural revolution. 

The main strengths of the diet are said to help people lose weight, curb appetites, and improve cardiovascular health. This diet does avoid processed foods and sugar, which is a plus, but it also avoids grains, legumes, and dairy which are good sources of various nutrients. Paleo is also a type of low-carb, moderate-to-high-protein, and high-fat diet.

  • TO EAT Animal sources: wild game, fish, shellfish, eggs, organ meats, lamb, pork, poultry, grass-fed beef, and turkey. Plant sources: fresh fruits, leafy vegetables, sea vegetables, cruciferous vegetables, root vegetables, herbs, spices, nuts, and seeds. Oils: tallow, lard, extra-virgin olive, avocado, flaxseed, macadamia, coconut, walnut, almond, and hazelnut. Beverages: filtered water, spring water, broths, herbal tea, coconut water, freshly juiced fruits and vegetables. Sweeteners: honey. Other foods: real salt, Himalayan salt.

  • TO AVOID Animal sources: dairy and its derivatives, factory farmed meats, eggs, and seafood. Plant sources: grains, beans and legumes. Oils: soy, cottonseed, corn, sunflower, and safflower. Beverages: processed juices, sodas, coffee, carbonated water, and alcohol.  Sweeteners: sugar, refined sweeteners, artificial sweeteners. Other foods: all processed foods, refined salt.


  1. High vegetable & fruit consumption

  2. No white/refined carbohydrates

  3. No processed/packaged foods

  4. Selection of grass-fed, local meats

  5. Weight loss is typical

  6. May encourage farmer’s markets

  7. Short-term metabolic improvements & reduction in BMI/weight (1)

  8. Promotes satiety and it may reduce overall calorie consumption for some (2)


  1. Whole grains and legumes are important sources of nutrients, such as ergothioneine, fiber, folate, copper, manganese, molybdenum, and many others that are decreased/eliminated in this diet.

  2. Not sustainable in our current day and age (3)

  3. Large animal consumption high in saturated fat which is linked to health problems.

  4. Not enough large body of research to support the claims.

  5. Hard to maintain a restrictive lifestyle which can cause harmful weight cycling.

  6. Not a lot of Paleo offerings outside the home and can be hard to maintain when traveling or visiting with others.

  7. A long-term very-low-carbohydrate diet may affect overall health, cognitive function, energy levels, athletic performance, and metabolism.

There are great merits to this diet, but it is not perfect. By following this diet you may be eliminating or excluding key nutrients. For any diet, it is important to meet with registered dietitians who are nutrition experts to ensure you don’t put your health in jeopardy to lose a few pounds. If you are thinking about trying this diet, it is beneficial to plan with a registered dietitian who can make recommendations on how to get all the nutrients you need while sticking to the Paleo diet outline.



The Ketogenic Diet   was an experimental diet for epileptic children that was proved beneficial in the 1920s. Since then, more research has pointed to ketogenic diets as the go-to nutrition plan for those with epilepsy. Ketogenic diets have recently been looked at for weight loss and some have been using ketogenic diets with claims of improving overall health, prevention of diabetes, treating obesity, improving insulin, improving athletic performance, and reducing body fat. The research is very limited for ketogenic diets in these areas.

The ketogenic diet hinges on eating a very low amount of carbohydrates to get your body into a state of ketosis -- where you are making ketones. Ketones are organic compounds used as energy sources that are made during starvation or in this case, also during very low carb diets. 

When our body goes into starvation or ketosis, we release fatty acids from our stored fat tissue. The fatty acids then enter our cells moving to the mitochondria. There, they are broken down and oxidized, becoming ketones -- which are released by the liver into our bloodstream. While in our blood, ketones can be taken up by different cells and used for energy. So, basically, your body is using your stored fat as energy, saving you some calories. ​

  • TO EAT

Small amounts of Protein: beef, poultry, pork, fish, seafood, organ meats, game, and eggs. Small amounts of low carb Vegetables: leafy greens, cruciferous vegetables, garlic, onions, leeks, cucumber, tomatoes, peppers, eggplant, mushrooms, tomato, zucchini, herbs and spices, low/no sugar fermented vegetables, sea vegetables. Small amounts of low carb Fruits: berries, citrus. Very high amounts of Fats: MCT oil, avocado and its oil, macadamia and its oil, Brazil nuts, coconut oil and other coconut products, olive oil, olives, lard, tallow, chicken fat, duck fat, goose fat, nuts and nut butters, seeds and seed butters, bacon, fatty fish, seafood, egg yolks, mayonnaise, butter and ghee, cheese, heavy cream, sour cream, and whole yogurt. Beverages: water, broth, coconut and almond milk, unsweetened coffee and tea, hard liquor. Other foods: shirataki noodles, >90% dark chocolate and cocoa powder/butter, mustard, hot sauce, vinegar.


Most fruits  Grains Beans and legumes  Other dairy products Starchy vegetables Slightly sweet vegetables like carrots, squash, or beets Processed foods Artificial sweeteners Refined fats and oils Other alcoholic drinks Factory farmed meats and fish


  1. Ketosis is generally safe for healthy people. 

  2. Healthy people’s bodies can self-regulate so it can maintain pH levels through a state of ketosis -- which raises acid levels in our bodies. 

  3. If you do not have medical conditions, you may possibly do this diet safely, but the only benefits that are scientifically evident right now are in reducing weight/body fat (5)in regular people, helping epileptic populations against neurological damage (6), and improving behavior in people with autism. 


  1. Ketosis can be very dangerous for pregnant women, diabetics, alcoholics, or others who may have metabolic mechanisms that are not properly working.

  2. Those as stated before who have diabetes or other chronic conditions may not be able to regulate the raises in acidity and therefore can enter into ketoacidosis, which is uncontrolled ketosis and very dangerous.

  3. This diet is picking up in popularity, but it remains largely unstudied because it is a very difficult diet for people to maintain.


Ketogenic diets are very low-carb and very high-fat diets. Where Paleo was lower than the typical American diet with around 20-40% of daily calories from carbs, down from the average of 60%+ carb consumption, the Ketogenic Diet gets only 5% of daily calories from carbs (4). 


  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4588744/

  2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3009971/

  3. https://spoonuniversity.com/lifestyle/why-the-paleo-diet-is-actually-hurting-the-environment

  4. http://www.precisionnutrition.com/ketogenic-dietpmc/articles/PMC2716748/

  5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3826507/

  6. https://www.ncbi.nlm.nih.gov/

May 11, 2017

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