The popularity of various (‘fad’) diet methods, such as the Atkins, The Zone, South Beach, and Protein Powder diets, have come in and out of fashion over the last few decades. I actually remember seeing an array of Atkins diet books on my parents’ shelves when I was younger, and at uni plenty of us tried protein shakes for some time or another. These low carbohydrate and calorie diet plans are generally based on one of two genetically-based concepts; either evolutionary nutrition, or what’s known as the thrifty gene theory.
For now, all you need to know about the thrifty gene theory are the basics; that early humans lived on a ‘feast or famine’ type of diet, with natural selection targeting those which could store excess energy as body fat. Unfortunately, this previously useful body fat has now supposedly led to a predisposition for conditions like type 2 diabetes in people today. But, the thrifty gene theory has been convincingly proven unlikely – mainly due to the lack of high carb foods (i.e. grains or sugars) in a time before the agricultural boom.
On the other hand, evolutionary nutrition is grounded in the idea that humans, and our diet, are adapted to the Palaeolithic (Oldest Stone Age, c. 3 million – 10 thousand years ago) era of hunter-gathering. The enormous contrast between what we’re apparently supposed to be consuming and today’s diet is what is causing modern epidemics of obesity, diabetes and related conditions. Evolutionary nutrition has not yet been rejected or proven wrong – at least not completely.
The Paleo Diet falls into the evolutionary nutrition diet category. The Paleo Diet was originally coined by Loren Cordain (Ph.D), but the idea has branched out so much that there’s even a ‘Paleosphere’ online, with bloggers, vloggers and celebrities alike joining the active and healthy ‘hunter gatherer’ lifestyle!
Cordain’s Paleo Diet is one of the stricter dietary outlines, and claims to consist solely of pre-agricultural food types. The basic outline for the Paleo Diet is just here.
|Table 1: Paleo Diet Food List|
|Grass fed meats/ meat products||Cereal grains|
|Fish/ Seafood||Legumes (including peanuts)|
|Fresh fruit and vegetables||Dairy products|
|Nuts and seeds||Potatoes|
|Healthful oils (olive, walnut, flaxseed, macadamia, avocado, coconut)||Processed foods|
|–||Refined vegetable oils|
There are quite a few books by Cordain on the diet, with different versions for beginners and athletes and so on. The Paleo Diet website is pretty good though (why not check it out), and has plenty of articles with tips, plans and recipes. Most of the recipes look normal, or even tasty, but there are a few on there which may not appeal to everyone, like the ‘Apricot Raisin Tongue’, ‘Stinging Nettle Saute’ or the ‘Bone Broth’. These are the ingredients (maybe not so much the Apricot-raisin flavouring bit) which resemble an ancient hunter gatherer diet the most though!
So, I got to thinking, and eventually researching – how Palaeolithic is the strictest Paleo Diet really? How similar is the diet we’re media-fed today to the one which is claimed to be THE ONE which we are genetically adapted to?
Here is my best summary of what I found!
The genetics of it seem to be…
Our hunter gatherer ancestors represent approximately 84 000 generations, with comparatively few human generations living since the agricultural (350 generations), and industrial (7 generations) revolutions. Over this time, as humans dispersed across the world, different races emerged, contributing approximately 3-5% to genetic diversity between populations. Despite these variations, we are genetically one species, and a species which has been claimed to still be optimally adapted to these original hunter gatherer environments.
The modern lifestyle and diet has changed drastically since this earliest hunter gatherer period, unhinging this delicate genetic balance, and potentially impacting human epigenetics (not inherited DNA, but externally effected). The changes have also likely occurred too rapidly for our bodies to genetically deal with these new foods, leading to an increase in rates of dietary and metabolic syndrome(s), like coeliac disease, and dietary deficiencies (vitamins A and D, iron, and Omega 3). The Paleo Diet claims to restore human diet to that of the genetically ‘ideal’ hunter gatherer ancestors.
Other information seems to suggest otherwise though…
This genetic idealism relies on hunter gatherer homo ancestors living off of the same, or at least very similar, diets. Which is just not possible!
It can be said for certain that Upper Palaeolithic (between about 40-10K years ago), let alone the whole of the Palaeolithic, resources and diet were very complex, and not at all similar!
Ancient hunter gatherers undeniably had a varied diet, whether within one lifetime, or across populations. For example, compiled archaeological remains and isotope data indicate a major temporal transition throughout the Palaeolithic to a broader diet, which was less meat-heavy and as equally reliant on aquatic and plant resources. Geographic location and variation also impacted dietary resources, with regional and more local diets appearing throughout the Palaeolithic. The higher latitude of northern archaeological sites potentially created a lack of edible plant material to be consumed, which was then compensated for by the increase in aquatic resources.
More information is also now proving that the hunter gatherers-farmer transition was not straightforward or abrupt. Some hunter gatherers would have even been consuming some starchy foods including grains and cereals. So those carbs and grains which have been so rejected in modern diets aren’t necessarily that bad!? Well, just maybe!
More recent (I mean since like the Victorian period), and modern data has also been collated on remaining hunter-gatherer societies, and used as a reference for potential ancient diet. This data also shows significant variation between populations! The graph below shows just some of the differences recorded.
Whether in the Upper Palaeolithic, historic, or modern period, hunter gatherer diet is dependent on certain factors;
- Climate; environmental impact
- Location; longitude, latitude and altitude, coastal or inland
- Demography; competition for, or over-exploitation of, resources
- Dietary preference
There are a wide range of dietary behaviours among hunter gatherers as a response to these factors. So, the main conclusion from the research for me is that no single or typical diet could possibly reflect all hunter gatherer populations, although the Paleo Diet does seem to try and suggest this. From this you could also argue that the Paleo Diet is also not the healthiest diet for us, denying us of nutritionally beneficial ingredients like whole grains, and the stability of more modern food production. Clinical trials involving the Paleo Diet generally show no significant difference or improvement in health markers compared to other diets.
Humans are ultimately a combination of inherited hunter gatherer adaptations and more recent evolution. So, a diet using this combination would surely seem like a better option…? Let’s see if the Paleo Diet sticks around or returns to the past!
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