An Ancestral Diet: A New Approach to the Ketogenic Diet

ancestral diet ketogenic approach sara alam sara aguilar

Here is An Ancestral Diet Approach to the Ketogenic Lifestyle: This text is based on my presentation at the Keto Festival in Bristol from March 2022. 

How we can use ancestral wisdom to cultivate a healthy, flexible and wholefoods approach to the ketogenic diet: an ancestral diet, and by wholefoods I do not mean grains. 

The secret to cultivating true health can be found in the wisdom of our ancestors.

I am challenging the strict ketogenic view and encouraging you to consider a more flexible approach.

By exploring ancestral, geographical, circadian, and seasonal patterns of eating and living, we can learn how to become our healthiest selves. Why? Because we are all individuals, with completely unique genetic and ancestral backgrounds, health, and lifestyles. There is no ‘one size fits all diet’. Fundamentally, nutrition and diet should be driven by health, not by dogma.

ancestral diet ketogenic


What I don’t want you to take away from this is that there is only one route to health, what  I want us to think about is how we can use the best of ancestral wisdom and modern-day science and knowledge to adapt our nutrition.

My argument is based on archaeological, palaeontological and anthropological evidence and sources supplemented by contemporary research, as well as 5 years’ experience with the ketogenic diet and working with my audience, here at Keto Supplements.

Let’s start by looking at what a strict ketogenic diet is and how it works and why we can use both ketones and glucose for energy.

What is the ketogenic diet?

A strict ketogenic diet is made up of 70-80 percent fat, 15-20 percent protein and 5 percent carbohydrates. The aim of the ketogenic diet is to transition your metabolism from using glucose for energy to ketones, AKA Ketosis. Ketones are energy molecules that are produced in the liver from the nutritional fat that you have consumed, or from mobilising your own body fat cells for energy.

What are the Benefits of the Ketogenic Diet?

Ketosis is metabolically efficient, and ketones are a clean burning fuel that provide a stable source of anti-inflammatory energy to the body, and in particular, the brain. The benefits as you know are myriad:

  • Stabilised blood sugar levels
  • Optimise cognitive function and repair
  • Fat loss
  • Increased physical endurance
  • Alleviate some chronic inflammation and the related health issues.

Is there an Ancestral Origin of Ketosis?

An Ancestral Diet: Why do we have the metabolic agility—or flexibility—to use both ketones and glucose?

The body has evolved to mobilise fat stores for energy for times of famine and during periods in which there is a shortage of food. Imagine our hunter gatherer ancestors having to hunt—potentially for days—without finding food. They need a stable source of energy that switches the brain on, heightening their sense of smell, hearing and endurance. Being ‘hangry’ when you need to hunt (feeling low energy, having a foggy brain and irritability) serves no purpose for a successful hunt. That is if you are relying solely on glucose.

We have evolved to use ketones for fuel to survive when there are no sources of carbohydrates, to become better hunters. This is exactly why the ketogenic diet is so often used by athletes, biohackers and high performers to optimise their cognitive focus.

The Ketogenic Diet Mimics fasting—the starvation state.

However, the ketogenic diet mimics fasting—the starvation state—putting your physiology on hyper alert—so long-term, it may not be the optimum metabolic state to stay rigidly in. This is why (anecdotally) women have found that following a rigid ketogenic diet can disrupt their hormones and fertility cycle—because extended ketosis indicates that there is a time of famine, food shortage or war or an extended winter in the northern hemisphere. I know from my own experience that a strict ketogenic diet cant disrupt your endocodrine system and I feel that I have a responsibility to let you know. And it can also disrupt sleep as the stress of mining for energy causes excessive cortisol release.

When were our Ancestors in Ketosis?

An ancestral approach considers circadian and seasonal rhythms as well as geographical location, lifestyle, and environmental demands. For the modern-day person, we adjust this to include sex, individual health and personal goals.

Throughout our evolution we would have flexed in and out of ketosis—rather than adhering to strict keto or a purely carbohydrates only based diet depending on the geographical and seasonal availability of food.

Ancestral/Palaeolithic approach takes into account:

  • Your own ancestry and genetic makeup—individualised approach
  • Food availability Geographical
  • Food availability Seasonal
  • Circadian, food consumption and physical movement throughout the day
  • Other variables: Lifestyle: Physical activity, personal goals, illnesses

ancestral diet

With all of these evolutionary, geographical and seasonal variables, we need to look at history, archaeology in particular, to ascertain the human diet that our ancestors evolved on.

It takes us 40,000-100, 000 years to physiologically evolve—implying that we may not be adept at digesting and utilising modern processed foods—potentially demonstrated in the prevalence of chronic illnesses, known as the diseases of civilisation.

Using References Archaeological Material Evidence from the last One Million Years. How can we figure out if we Were we Hunters, Gatherers, Foragers or Scavengers?

ancestral diet

Were we herbivores, carnivores, or omnivores?

Some of the evidence is quite actually contradictory. It appears that we were likely all of these depending on the environmental, geographical, seasonal influences.  Let’s look to some archaeological and paleontological evidence:

We hear from an evolutionary nutritionist, Loren Coordain that A Stone Age diet “is the one and only diet that ideally fits our genetic makeup,” author of ‘The Paleo Diet’. And that if we stick to the foods our hunter-gatherer ancestors once ate, we can avoid the diseases of civilization, such as heart disease, high blood pressure, diabetes, cancer, even acne.’ However, the paleobiologist Amanda Henry agues that “What bothers a lot of paleoanthropologists is that we actually didn’t have just one caveman diet,” as we need to consider geographical location and the changing climate.

An Ancestral Diet: You are what your ancestors ate.

If we are what our ancestors at?  What constitutes the so-called Stone Age or Cave Man diet?

Archaeological remains from a million years ago give us our most reliable insight into what early hominins ate. Archaeologists have found remains of early hominins alongside speared large mammal carcasses (such as mammoths) as well as large weapons and hand axes. There are artefacts of stone tools, cut marks, spears, anvils and markings on animal carcasses demonstrating that humans used tools to break into animal marrow, crania and large upper limbs and muscular meaty flesh.

That was a million years ago, Bone artefacts from 200-100,000 years ago from archaeological sites show fossils of fresh and brackish water fish and shellfish, as well as bones of medium sized herbivores with marks of being hunted.

Demonstrating that early humans hunted, rather than scavenged.

As time progressed and the Post Glacial Warming began, the tools discovered with humans became more complex and the prey remains became smaller. The development of hunting tools, more adept foraging, control of fire and use of clothing lay behind the success of human adaptation to the harsh palaeolithic environment.

Let us consider the teeth of early hominins (1,000,000 years ago)

 diet molars tubors

‘The large molars and premolars of the robust Australasian early hominins…suggest a diet of gritty foods such as seeds, roots and tubers.’ Implying that Plant foods formed the bulk of the early hominin diet, with animal foods an important but smaller portion of their food intake. Hence a fibrous rich diet of plant foods; a nod to a herbivore diet.

Having looked at odonatological material evidence (teeth) in a historical context, let’s now correlate this with contemporary physiological research. Let’s look to some contradictory physiological evidence.

Story of the teeth says that we are ideal for a herbivore or plant based omnivorous diet.

 diet gut length humans verse dogs

The gut tells us that our colons and large intestines are too short to deal with cellulose and fibre from plant matter.

We have larger small intestines than other primates (the small intestine is for processing meat and our colon lengths are similar to that of a dog and a cat). Dogs and cats are carnivorous, and our guts are similar in length and we have smaller stomach fermentative capacity in contrast to primates.

If our teeth are closer to chimps and our guts are closer to cats and dogs, what does that suggest for the ideal human diet?

The gut suggests that we are more biologically suited to a carnivorous diet yet our teeth tell a different story. Hence the idea that ancestrally and physiologically, an omnivore diet makes more sense.


Use of Stone Tools – may have coincided with brain growth:  ‘A significant inclusion of animal protein in the hominin diet, accomplished through the use of tools, may have provided a critical impetus to the rapid evolutionary expansion of brain size in the hominin lineage.’ It is fair to deduce that if we evolved solely on a plant based diet we would not be as intelligent as we are. (P 78 The Human Past)

In 1995 Anthropologists: Leslie Aiello and Peter Wheeler coined:

‘The Expensive Tissue Hypothesis’

‘Animals with diets that include large amounts of low-nutrient plant foods tend to have more complex digestive tracts and need to devote more metabolic energy to digesting and detoxifying these foods. Animals (such as carnivores and omnivores) with diets characterized by higher-quality foods (high in protein and calories, such as meat and fat) tend to have simpler, more streamlined digestive tracts and need substantially less energy for digestion, often allowing these species to evolve larger brains. An omnivorous diet would allow more metabolic energy to be devoted to a larger brain. Therefore, tool use, meat/marrow consumption, and brain expansion all evolved in tandem.’

This further correlates the argument that we need animal sources of protein and fat to thrive as intelligent humans with larger brains. But does not suggest that we ate exclusively meat. A more omnivorous picture of our ancestral diets is clear.

foods for encephalisation 

 Post Glacial Warming: We have looked at stone age evidence and contemporary physiological research. Let’s look at the last 16,000 years, characterised by the Post Glacial Warming—in which the earth’s environment underwent huge changes.

Is global warming always a bad thing? For the last 16000 years, temperatures have risen, causing sea levels to rise, creating more islands and the deglaciation of previously uninhabitable land allowing more biodiversity and vegetation. This gentler Holocene period, created a life–rich environment, supporting the survival and thriving of the human species. These environmental changes entailed the global redistribution of human population to more land mass; an abundance of food availability: from both the land and the sea.  The human diet shifted from hunting large mammal to smaller mammal and seafood as well as subsisting on plants, roots and fruits depending on the geographical location and season. Serving as critical nutrition for humanity and demonstrates a shift from an early carnivorous diet  towards a more omnivorous way of eating. 

 Food Collectors to Food Producers

Enter the millennia of early Agriculture from approximately 2000 years ago. This entailed the domestication of plants and animals, the cultivation of fields, sowing, harvesting and storing seeds. Pasture and Herding changed the relationship between humans and animals. Agriculture allowed food security and the reorganising of human society, creating committed relationships with plants and animals, deforestation for fields, (plows, field systems, irrigation) and resulting in more villages, more people and an increased pace towards more complex social and political organisation. Food became far more easy to access, yet with questionable nutrition. Enter the word of calorie dense, nutrient depleted foods. For the first time in human evolution we have access to more energy than we expend. All hail chronic illnesses.

 Did we give up a healthier diet and stronger bodies in exchange for food security? 

It appears there are no black and white carnivore verse herbivore arguments for the human diet. All we can do now is look at some more recent anthropological examples of communities who are closest to our living ancestors and existing Hunter Gatherer Tribes. We can ask: are they healthy? What to they eat? How do they live?


plant based diet hadza of tanzania

The Hadza of Tanzania are the world’s last full-time hunter-gatherers giving us incredible insight into our ancestors. They live on what they find: game, honey, and plants, including tubers, berries, and baobab fruit. An omnivorous moderate carbohydrate, low fat and moderate protein diet which is an ancestral diet for this region.

keto inuit of greenland

Now we have the Inuit of Greenland who have survived for generations eating almost nothing but meat in a landscape too harsh for most plants. This is a completely carnivorous diet that is high fat and high protein and almost zero carbohydrate—we could refer to this as a stone age diet. But is this an ancestral diet?

The disparity between the two equally ancestral tribes demonstrates that that there is more than one ancestral diet depending on what part of the world your ancestors evolved.

These dietary developments are so much a product of food availability, season, geography, and other varying resources.

Geographical and Seasonal Influences on an Ancestral Diet

Considering all of this information on the vastness of the evolutionary spectrum, from looking at our teeth, to our guts, to archaeological remains and contemporary hunter gatherer tribes, how could we not argue in favour of the uniqueness of ancestors’ dietary evolution and subsequently that of our modern counterparts.

How do we use this information to inform ourselves and how do we adapt a ketogenic diet to suit our own individual ancestry?

In a world plagued by chronic illnesses (related to diet and lifestyle)—can we fuse the best of ancestral wisdom and modern-day technology to optimise all areas of health. Yes, we can! And in order to apply an ancestral approach to the ketogenic diet, consider Geographical, Seasonal, Biological and Circadian Rhythms.


 Where did your ancestors evolve? What did they eat? Depending on how close to the equator our ancestors lived would influence the foods that they had access to as we saw with the Hadza tribe in contrast to the Inuit.

For example, in the Northern Hemisphere vegetables and leafy greens would have been available during the spring, summer and autumn. Fatty land animals, game and predominantly seafood would have been staple sources of nutrition throughout the winter months and fatty animals feature heavily in cave paintings as prized catches.The closer to the Equator your ancestors evolved, indicates an increased access to fruits and vegetables all year around with more limited access to fatty land animals but likely access to seafood, game and rodents as well as insects.

I also want you to think about the Season: What time of the year is it—where you live—what would naturally be available?

 In general food access is more abundant in the summer and autumn—a time to store fat to survive the cold winter months, an ancestral diet. Carbohydrates, glucose, insulin = growth hormone fat storing hormone too.

Perhaps the winter is an optimum time to follow a ketogenic diet as it aligns with the natural availability of food and tunes us into seasonal rhythms. We need periods of lack and periods of abundance as this creates the equilibrium and homeostasis that our bodies strive for. The ebb and flow of natures’ rhythms, be they circadian, seasonal or evolutionary.

I would also like us to take into account Biological Rhythms: Gender differences:

For women, I advise that you adjust the ketogenic diet for your hormonal cycle. That is to consume more carbs prior to menstruation as this promotes progesterone production which can also alleviate cramps and pmt. A long term severely restricted keto diet has been known to  cause no periods and even hair loss.

From a Natal Perspective: We are all born in ketosis. Human babies are one of the only mammal species with rolls of fat, so that if the mother cannot produce milk, the infant can survive through utilising its own fat stores.. Breast milk is also high in MCTs which are easily converted into ketones in the liver. This is why MCT Oil is so popular on the ketogenic diet as it makes it easier to get into ketosis.

ancestral blueprint keto diet

To reiterate: we are born to be metabolically flexible to be able to use both ketones and glucose for our survival evolution.

Considering this, let’s what other factors can we take into account for our own diets and lifestyles?

Circadian Rhythms

The documented daily rhythm from our ancestors is that they would have lived according to the sun and moon; day and night without the obtrusion—and obvious benefits—of modern light, heat and electricity. On waking they would have had to move, get out into the sunlight and either hunt, forage, prepare food, organise their physical home or socialise with their community.

Our ancestors moved—lot—and they had to work for their food, therefore they likely awoke in ketosis following an extended fast that would have ended at daylight or on their fire being put out at night. Our ancestors would have likely eaten once or twice a day, spent the morning either hunting or foraging. Their ability to be in ketosis would have been critical to their survival. A nod to intermittent fasting and OMAD (One Meal a Day) as being aligned with our ancestral evolution—getting us into ketosis but not necessarily following a ketogenic diet.


Consider where your ancestors are predominantly from. Where you are geographically based, your sex, your lifestyle, health issues and goals. Biologically, we have the agility to use both ketones and glucose for fuel and they serve different purposes. Our ancestors would have dipped in and out of each—that metabolic flexibility is truly ancestral, especially when deployed in accordance with geographical, circadian and seasonal rhythms.

ancestral diet ketogenic paleo health

In summary: How can you adjust a ketogenic diet to suit you?

 Achieving true health, the absolute healthiest version of you goes beyond simply following macro measurements. This is because there are so many facets to health: such as movement, community, sleep, environment and purpose.

A flexible, ketogenic diet takes into account our individual ancestry, where we are in the world, the season and your lifestyle and health.  

We are unique and we will adapt just as our ancestors have. When choosing a diet or lifestyle, be aware of you own uniqueness. There is no ‘one size fits all diet’. Fundamentally, nutrition and diet should be driven by health, not by dogma.

I would love to hear your thoughts on the ancestral diet. Please leave your comments down below.


Keep reading: Seed Oils, 

3 thoughts on “An Ancestral Diet: A New Approach to the Ketogenic Diet

  1. Rex Wiig says:

    Sara, Fascinating! I love the research and discussion into our true dietary legacy. Our diets have changed dramatically in the past 10K years and not nearly enough for us humans to evolve ourselves to adjust for these changes. I am convinced this is a cause of many health issues in the world today. One thing that gives us a clue that our bodies are designed to eat meat, as you elude to in your article with the relation to our similarity to dogs digestions, is our inability to make our own vitamin B12 which is crucial to life! Humans can only get that essential critical life giving vitamin through the ingestion of meat, dairy, eggs, fish…

    There is also some thought due to our heavily processed western diet and the heavy use of antibiotics, that the human gut microbiome is becoming extinct and there is a move to collect feces from indigenous tribes in the Amazon and bank those.

    Anyway love your tie in to ancestral diets. That is so important.


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