Paleo, Low Carb and Keto - Which Is Best?

Carbohydrates are a hot topic in the Paleo world.  Although not strictly defined as such, the relatively low-carbohydrate nature of the Paleo diet provides a plethora of health benefits.  The question of how many carbohydrates your Paleo diet should  include for optimal health is often raised.  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, both carbohydrates and protein need to be tightly controlled.

So What Exactly is a Ketogenic Diet?

The Ketogenic diet is by definition a low-carb, moderate protein; high fat diet that often needs to be very low carb to achieve its purpose of burning fat for energy through the creation of 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 by-product. Stored fat, dietary fat and ketones are all used in this metabolic 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 carbohydrate threshold for ketosis varies between individuals however for most people; reducing carbohydrate consumption to below 50 grams becomes necessary to maintain this metabolic state. Based on a 2000 calorie diet, this is less than 10% carbohydrate. Individuals who are highly carbohydrate sensitive, such as those with metabolic syndrome or type 2 diabetes will require even less, 20-30 grams of carbohydrate per day to cross the threshold. Protein is moderated at 10% to 15% of intake, or about .5 grams per pound of body weight. However, just as ideal carbohydrate intake varies, ideal protein intake varies too. Fat makes up the difference at 70 to 80% of daily calories.

The Paleo/Keto Comparison

This very low-carb, moderate protein, high fat diet can appear to be in stark contrast to the Paleo nutrition plan. The macronutrient intake of Paleolithic man varied considerably according to location, climate and season, although there were most certainly societies that thrived at both ends of the carbohydrate spectrum. Recommendations for current Paleo diet macronutrient ratios are not clearly defined because although food quality is strongly emphasized for everyone, meal composition depends on individual needs, preferences and goals. Between 50 to 80 grams of carbohydrate per day can allow for ketosis to be present if necessary. 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 lower in carbohydrates than the Standard American Diet, the ketogenic diet requires rigid adherence to a macronutrient profile that will get you and keep you in ketosis. The Paleo diet keeps blood sugar controlled and creates fat adaptation, but does not 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 Paleo diet and the ketogenic diet have been shown to be anti-inflammatory in nature. Inflammation is increasingly recognized as the root cause of all chronic disease and both diets are associated with a vast array of health benefits including but not 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 ketogenic diet, the Paleo diet restricts some foods from the industrial era and beyond. Full-fat dairy such as heavy cream, cream cheese and hard cheeses are often added to meals to help meet the high fat requirement. Raw dairy has become popular in some ancestral diet communities and consumption depends on tolerance and its potential pro-inflammatory effects.
• When considering adaptation, it may take two to three weeks to transition through the symptoms often experienced when shifting to the Paleo diet. These include flu like symptoms, fatigue, headaches and general malaise as the body begins to adapt to consuming more nutrient dense foods and less quick, nutrient poor sources of energy (refined foods). It may take as several days to several months to fully adapt and start feeling optimal on a ketogenic diet and some people may never adapt to it.

Very low carbohydrate diets are often contraindicated for women who are pregnant or having fertility issues, athletes whose sport demands high glycolytic output, and those with hypothyroidism or adrenal fatigue.

Myths & Truths - Which Protocol is the Right Fit For You?

There are numerous myths, truths and assumptions made regarding carbohydrate consumption and Paleo and ketogenic diets:

• Paleo does not imply very low carbohydrate or ketogenic diets by default.

Some low-carb advocates have claimed that most traditional hunter-gatherer societies consumed diets that were very low in carbohydrates. These claims are false. The majority of studies have shown that traditional hunter-gatherer (HG) societies typically consume between 30–40% of their total calories from carbohydrate, though the range can vary between 3–50% depending on the population studied and the latitude at which they live. There is further evidence of specific ancestral populations—such as the Kitava, traditional Okinawans, and Tukisenta—that consumed between 70–95% of calories from whole-food carbohydrate. The only traditional hunter-gatherer societies that have been observed to eat fewer than 20% of calories as carbohydrate were those living at latitudes quite distant from the equator (like the Inuit of the Arctic), often in environments where fruits, vegetables, starches, and honey were not readily available.

Even these societies often made an effort to obtain carbohydrates from berries, corms, nuts, seaweed, and tubers whenever they could. It is further highly unlikely the Inuit spent much time in nutritional ketosis due to their high protein intake.

I have no doubt that ancestral diets and those of our Paleolithic ancestors were lower in carbohydrates than the current Standard American Diet which comprises 40-65% of calories from carbohydrates, although they were not typically very low (less than 15% of calories) carbohydrate. With virtually no historical examples of human beings following ketogenic diets for any significant length of time, and few examples of very low-carb diets, it is difficult to understand how these eating plans could be considered the default nutritional state or the optimal approach for most people.

• Carbohydrates from whole, real foods are assimilated differently by the body than those from refined processed products.

I am often amazed to hear ‘experts’ speak about how all carbohydrates are the same. The basic premise of the Paleo diet is that foods as they are found in nature are healthier, more nutritious, absorbed better and are more beneficial than those made in factories and processing plants. When it comes to food, and in this case carbohydrate, quality trumps quantity every time!

As discussed, most hunter-gatherer societies consumed on average 30–40% of their calories from carbohydrate. These carbohydrates came from starchy tubers and plants, whole fruit, and in some cases, honey.

Despite this liberal consumption of carbohydrates, these communities were always observed to be lean, fit, and free of chronic, inflammatory diseases like diabetes, cardiovascular disease, and neurological conditions.

What is consistently observed is that these cultures acquire modern disease when they adopt a modern diet and lifestyle, complete with the highly processed and refined foods that characterize it. 

• Low-carbohydrate diets are incredibly effective in certain situations.

Low carbohydrate diets can be incredibly effective therapeutic tools for certain conditions.

These conditions include (but are not limited to):

1. Overweight and obesity
2. High blood sugar
3. Metabolic syndrome
4. Diabetes (both type 1 & type 2)
5. Traumatic brain injury
6. Epilepsy
7. Parkinson’s disease
8. Alzheimer’s disease
9. Other neurological conditions
10. PCOS

A possible downside to the ketogenic diet...

Yet as impressive as very low-carbohydrate (VLC) and ketogenic diets can be in certain situations, these protocols have some undesirable side effects over the long term. Preliminary research suggests that long-term ketogenic/VLC diets may cause adverse changes to the gut microbiota. In addition diets low in ‘microbiota-accessible carbohydrates (MACs)’ have been shown to contribute to modern, inflammatory disease.

MAC’s are the numerous  fibers found in fruits, vegetables, starchy plants, nuts, seeds, legumes, and other foods that are poorly absorbed by your digestive tract, but can be utilized as a food source by your intestinal bacteria. Many of these fibers are found in foods with moderate to high carbohydrate content. These foods that would typically be excluded on very low-carb diets but comprise many of the whole food starches that form part of the Paleo protocol.

The detrimental effects on the gut microbiome can be partially offset by consuming non-digestible, fermentable fibers like resistant starch and non-starch polysaccharides that don’t count toward daily carbohydrate intake.

• The fact that very low carbohydrate/ketogenic diets work therapeutically for certain conditions does not make them appropriate for all people in all circumstance.

This failure in logic happens often. You may know a person who has undergone a life-changing experience with a ketogenic diet, and assume you will have a similar experience. Clinicians working with conditions known to be successfully managed through very low carbohydrate diets also often make the assumption that all people, regardless of their goals, needs or health complaints will benefit from the same approach. 

This ignores the important differences that determine what is optimal for each person. These include variations in genes, gene expression, the microbiome, health status, activity levels, geography, living conditions, lifestyle factors and beyond. When it comes to diet, there is no one-size-fits-all approach. Some people do better on low to very low carbohydrate diets than others but this does not imply that everyone will have this experience. You only need to visit any of the online platforms to find numerous reports from people who either experienced no benefit from or were even harmed by following a low-carb diet. People eating too few carbohydrates for their personal needs may experience fatigue, lack of energy, stalled fat loss and sleep and mood disturbances.

Contra-Indications Of a Very Low-Carb Approach

Very low carbohydrate and ketogenic diets are contra-indicated (and may even be detrimental) for pregnant and nursing women, those struggling with adrenal dysregulation and hypothyroidism and people whose lifestyle demands are of a high energy nature, like athletes or those who are extremely physically active

Determining Your Optimal Diet Plan

The table below summarizes how you might want to determine your personal carbohydrate needs:

In conclusion, very low carbohydrate and ketogenic diets are an effective therapeutic tool in certain situations, and one many clinicians use in their practice. It becomes equally true that low-carb, very low carb and ketogenic diets are not appropriate in all circumstances, and they are certainly not the human default optimal nutritional state. It is important to view each person and their circumstances as unique and choose the nutritional approach in alignment with those specific symptoms, needs and goals.