There are many myths surrounding the paleo diet. One of the most prevalent ones being that ancestral diets are always very high in fat and meat. This notion probably stems from the fact that a lot of people associate ancestral nutrition with a low-carb approach and therefore assume that oils, bacon, and even cheese and butter are a major part of a contemporary paleo diet. In many ways, this confusion is warranted, as many contemporary paleo dieters seem to be under the impression that as long as they limit their consumption of grains, sugar, and refined vegetable oils, they can get away with eating an almost unlimited amount of fatty foods. However, the fact is that dense sources of fat such as GHEE, butter, and oils are not a part of the ancestral diet. This doesn’t mean that there’s anything wrong with eating these foods in moderation, but too much is generally not a good thing.
What did the first members of our species actually eat?
The paleolithic era is a prehistoric period of human history that lasted from the earliest known use of stone tools about 2.6 million years ago, up until the agricultural revolution about 10.000 years ago. Our species first emerge in the fossil record 200.000 years ago, and it’s believed that we stayed in africa until about 70.000 years before present.
What did these early african humans actually eat? We can’t say for sure, and the prehistoric human diet clearly didn’t stay constant throughout this period. What we do know is that early humans were omnivores who subsided on a diet that consisted of both wild plants and animals.
Based on anthropological data and studies of contemporary hunter-gatherers living in Africa, it seems that fruits/berries, tubers, honey, and meat from both small and large animals were an important part of the early african diet (1,2,3). Boyd Eaten, one of the first scientists who started looking into paleolithic nutrition, has the following to say about macronutrient intake in these paleolithic tribes:
Awareness of the ancestral human diet might advance traditional nutrition science. The human genome has hardly changed since the emergence of behaviourally-modern humans in East Africa 100-50 x 10(3) years ago; genetically, man remains adapted for the foods consumed then. The best available estimates suggest that those ancestors obtained about 35% of their dietary energy from fats, 35% from carbohydrates and 30% from protein. Saturated fats contributed approximately 7.5% total energy and harmful trans-fatty acids contributed negligible amounts. Polyunsaturated fat intake was high, with n-6:n-3 approaching 2:1 (v. 10:1 today)” (2).
These numbers have later been questioned and modified somewhat by other researchers, but it’s believed that they present a fairly accurate estimation of the diet of our ancient african ancestors. As you can see, fat intake is not especially high among these early humans. However, protein intake is; meaning that lean meats could have been a substantial part of the diet of these first humans. But, as we know, Homo sapiens didn’t stay in africa forever. What happened to the human diet when we started colonizing the world?
High-fat (50-60%+) hunter-gatherer diets are the exception rather than the rule
As I’ve previously mentioned many times on the blog, if we actually look at the diet of hunter-gatherers (both contemporary and prehistoric), it becomes clear that there isn’t one universal ancestral diet. As one would expect, food availability, macronutrient ratio, and plant-animal subsistence ratio depend on season, climate, location, etc, and while some hunter-gatherer populations thrive/thrived on diets rich in tubers, fruits, and vegetables, others eat/ate a more animal-based diet.
Subsistence data from 229 hunter-gatherer communities indicate a range of 28-58% for fat intake (4). This range is very broad because some populations, such as The Inuit, get a lot of calories from fat, while others, such as tropical islanders, get most of their energy from carbohydrate.
The fact is that unless the majority of your diet consists of fatty animal products or large amounts of coconut, it’s very difficult to get above 40-50% energy from fat in the form of ancestral foods. So, while it’s true that paleolithic diets are generally higher in fat and meat than the diet recommended by official health authorities in industrialized nations, the extreme examples of people eating massive amounts of red meat and lard are the exceptions rather than the rule.
Despite these differences, there are certain general characteristics that all ancestral diets have in common. 3 important factors:
- They consist of minimally processed, nutritious food.
- On average, they contain less carbohydrate (22-40%) and more protein (19-35%) than «modern diets».
- Grains and milk are rarely consumed, and vegetable oils, refined sugars, and other modern foods are absent.
Ancient humans clearly didn’t have access to very dense sources of fat such as coconut oil, olive oil, butter, and GHEE. Also, we have to remember that wild animals are different from domesticated ones; they are generally leaner and have a healthier fatty acid composition. Although primitive people “always” eat the fattest part of the animals they kill, few hunter-gatherer tribes have/had access to a steady supply fo fatty foods throughout the year.
What are the implications for paleo dieters?
I’ve always looked at ancestral nutrition as a starting point for healthy eating in the 21st century, not a strict set of rules. A contemporary paleo diet (everyday, modern foods that mimic the food groups of our pre-agricultural ancestors) is not about eating massive amounts of meat or stuffing yourself with oils and bacon. I recommend eating organic eggs, free-range meat, and seafood every day, but tubers and other vegetables and even some legumes (yes, some paleolithic tribes actually ate certain types of legumes) can make up a substantial part of your diet if you don’t want to eat a lot of animal products. Add an avocado or some coconut or olive oil and you’re good to go.
What are the implications for the society at large?
Low-carb diets are often criticized for their negative impact on the environment. However, it’s important to note that an ancestral diet isn’t necessarily low-carb or extremely high in meat, and even though a paleo dieter generally eats more animal products than someone who consumes a grain-based diet, he more frequently chooses grass-fed and organic produce. Also, it’s definitely possible to eat a low-carb diet without eating massive amounts of bacon and other fatty meats. Avocados, coconuts, and olives are just some of the plant foods that can contribute plenty of fats on a high-fat diet.