Paleo vs Keto


Carbohydrates are a hot topic in the Paleo world.  Although not strictly defined as such, the relatively low-carb nature of the Paleo diet provides a plethora of health benefits.  How many carbs should your Paleo diet include for optimal health?  The answer depends on many things including your gender, health status, stress level, activity level and your goals.   Some find greater benefits from going very low-carb in order to create and maintain a state of ketosis. Ketosis can occur as a transient adaptation to a low-carb Paleo diet but to stay in this state for any length of time, carbs and protein need to be tightly controlled. Let’s take a closer look.


The Ketogenic diet is by definition a low-carb, moderate protein, high fat diet that often needs to be very low carb to do its job of burning fat for energy and creating ketones. Protein intake is moderate in order to prevent gluconeogenesis, the process of turning non-carbohydrate substrate such as amino acids into glucose. When these conditions are met, fat rather than glucose becomes the preferred energy source and ketones are formed as a byproduct. Stored fat, dietary fat and ketones are all used in this elegant metabolic fallback system for energy production. Paleolithic people depended on ketosis for survival in times of food scarcity. Conversely, modern humans have harnessed it for weight reduction in an era of food over-abundance. The ketogenic diet has also been used therapeutically to treat medical conditions such as uncontrolled seizures in children, type 2 diabetes and obesity and there is increasing interest in the use of ketosis for neurodegenerative conditions such as Alzheimer’s, Parkinson’s and multiple sclerosis.

Screen-Shot-2014-05-30-at-3.54.25-PM-198x300.pngThe carbohydrate threshold for ketosis varies between individuals however as Jimmy Moore points out in his book Keto Clarity, almost everyone has to go below 100 grams of carbs per day and most will need to go below 50 grams. Based on a 2000 calorie diet, this is less than 10% carbohydrate. Very carb sensitive individuals such as those with metabolic syndrome or type 2 diabetes will require less than 30 grams or even less than 20 grams carbohydrate to cross the threshold. Protein should be moderate at 10% to 15% of intake, or about .5 grams per pound of body weight. However, just as ideal carb intake varies, ideal protein intake varies too. Fat picks up the slack at 70 to 80% of daily calories.

How does this super low-carb, moderate protein, high fat diet compare to the Paleo diet? The macronutrient intake of our Paleolithic ancestors varied considerably according to location, climate and season and although there were most certainly societies that thrived at both ends of the carb spectrum, ancestral diets are estimated to have been 20% to 40% carbohydrate, 15% to 35% protein and up to 65% fat. Recommendations for current Paleo diet macronutrient ratios are not clearly defined because although food paleoplan_021-300x204.jpgquality is strongly emphasized for everyone, meal composition depends on individual needs, preferences and goals. That said, recommendations generally fall within the realm of 10% to 30% carbohydrate, 10% to 20% protein and up to 70% fat. It’s at this level of carbohydrate intake where fat adaptation (the ability to burn fat more efficiently) and transient adaptation to ketosis might occur. Mark Sisson points out that at 50 to 80 grams of carbohydrate per day, ketosis kicks in when it needs to and at 100 to 150 grams per day, fat adaptation still occurs but ketosis is unlikely. This is the biggest difference between the two diets. Though they are both generally low carb, the ketogenic diet requires rigid adherence to a macronutrient profile that will get you into ketosis. The Paleo diet keeps blood sugar controlled and creates fat adaptation, but doesn’t necessarily induce ketosis.

Other noteworthy comparisons between the two diets include the anti-inflammatory nature of low-carb plans, the use of dairy and the length of time it takes for adaptation. Both the ketogenic diet and the Paleo diet are anti-inflammatory and as inflammation is increasingly recognized as the root cause of all chronic disease, both diets are associated with a vast array of health benefits including but far from limited to, the resolution of IBS, lowered blood pressure, lowered triglycerides, improved immunity, healing from autoimmunity, weight loss, improved glycemic control, increased mental clarity and increased energy. Unlike the Paleo diet, the ketogenic diet doesn’t have food group restrictions and full-fat dairy such as heavy cream, cream cheese and hard cheeses are often added to meals to help meet the high fat requirement. In regards to adaptation, it takes two to three weeks to get over flu-like symptoms known as the “Paleo flu” and adjust to the Paleo diet.  It may take as quickly as several days to as long as several months to fully adapt and start feeling good on a ketogenic diet and some people may never adapt to it.  In fact, low-carb diets may be contraindicated for women who are pregnant or having fertility issues, athletes whose sport demands high glycolytic output, and those with hypothyroidism or adrenal fatigue.

In summary, where strict adherence to a low carb, or very low carb, moderate protein, high fat diet is integral to success on a ketogenic diet, the Paleo diet is more forgiving. You may end up in ketosis on both diets, but you won’t necessarily stay in it on the Paleo diet. It may take longer to adapt to the ketogenic diet and if you don’t eat dairy products, incorporating adequate fat into meals can be a challenge. Although very low-carb diets may be contraindicated for some, both diets are associated with many health benefits and with experimentation and perseverance, you’ll undoubtedly find which plan works best for you.

Here’s to good health!


Selected Resources:

Keto Clarity: Your Definitive Guide to the Benefits of a Low-Carb, High-Fat Diet

Perfect Health Diet: Regain Health and Lose Weight by Eating the Way You Were Meant to Eat

Dear Mark: Ketosis

What Does It Mean to Be Fat Adapted

Is a Low-Carb Diet Ruining Your Health?