Can there be a diet more of the moment than the 'Paleo Diet' (OK, the 5:2 diet excepted...)? For the uninitiated (and I don't suppose there can be that many of you by now), it's a dietary (and lifestyle) dictum that encourages us to go back in time and adopt the dietary (and exercise) habits of our ancient hunter-gatherer forebears.
The Paleo Diet is based on the discordance hypothesis, a premise which argues that it is the departure from the nutrition and physical activity patterns of our hunter-gatherer ancestors that has contributed to the endemic chronic diseases of modern civilization (1). As researchers in this field note, "Socially, we are a people of the 21st Century, but genetically we remain citizens of the Paleolithic era" (2).
In essence, the Paleo Diet is based upon lean meats, fish, seafood, eggs, fruits, vegetables, nuts and 'good' fats. (Or, what I like to call 'real food'). Exiled to the nutritional wilderness are all those foods that didn't feature in our ancestral diet: grains, legumes, dairy products, and of course sugar, trans fats and processed foods of all kind.
Despite the relative lack of direct scientific evidence in support of the Paleo Diet at present (I am aware of two small RCTs that showed following a Paleo Diet promotes greater improvements in glycemic control and cardiovascular risk factors than either a Mediterranean-style diet (3) or a Diabetes diet based on American Diabetes Association guidelines (4)), and my usual skeptical disposition about anything resembling a diet craze, I have to admit to being somewhat seduced by the Paleo Diet concept.
After all, break it down, and it's a diet that neatly fits my broader sentiments for what constitutes a healthful diet, being rich in high quality protein, omega-3 fats, monounsaturated fats, fibre, potassium, vitamins, phytonutrients, only moderate in carbohydrates and with a low GI, and blatantly devoid of the multitude of processed crap (is there a better word?) synonymous with Western diets. Further, by excluding foods that are among the most common that people adversely react to (dairy, wheat, gluten), we have a diet that many people justifiably claim suits them well.
But the thing that really impressed me, above all else, was the compelling evolutionary and anthropological argument. It is the diet that we were genetically programmed to eat over millions of years, and abandoning it, in favour of 'novel' modern foods in just the last few thousand years, a mere blink of the eye in evolutionary terms, is the seeds of our collective health woes in the 21st Century. You just can't argue with that.
Well, as it happens, lots of anthropologists do. The paleo diet, as it is presented in the popular media, creates the illusion of a universal, homogenous, 'one-size fits all', meat-dominated, hunter-gatherer diet. But the reality is very different. In fact, hunter-gatherers expressed a diverse range of dietary behaviours that does not fall into one standard, universal, macronutrient pattern.
Whilst data on hunter-gatherer consuming traditional diets indicates that such societies are largely free of the diseases of civilisation, this is irrespective of whether a high proportion of energy is derived from wild animal foods (such as Canadian Eskimos), wild plant foods (such as the !Kung), or domesticated plant foods (such as the Yanomamo) (5). We should be talking about Paleo Diets (in the plural) not the Paleo Diet...
For those harking back to a pristine paleo past and under the illusion that they can accurately emulate just what their hunter-gatherer predecessors ate, think again. Domesticated, factory farmed, and fattened meats are a far-cry from wild prey. And where are the organ meats and bone marrow that would surely have been highly treasured pickings for our ancient ancestors? As for fruits and vegetables, they have been highly and selectively bred over generations and bear virtually no resemblance to the wild plants our ancient ancestors would have foraged. Yes, our modern fruits and vegetables are quintessential 'farmer's' food! As for grains and legumes, well, lo-and behold, remnants of these foods have been found in the fossilised dental plaque of hunter-gatherers. Check out this fascinating TEDx lecture by archaeological scientist Christina Warinner for much more on all of this. This is why some anthropologists refer to the Paleo Diet as the 'paleo-fantasy', which as Christina Warriner says, has "no basis in archaeological reality".
But before you jump to brand me anti-paleo, I will state loud and clear that I am very much pro a paleo diet perspective. However, rather than jumping on the bandwagon of a mythical, universal, one-size fits all Paleo Diet, with a whole bunch of really prescriptive and dictatorial dietary rules, I would rather redefine it as a diverse diet based around genuinely fresh, truly seasonal, local produce, in short the most unadulterated 'real' food you can get (just take a look at the wonderful rich picking of what's in season at the moment here). Isn't that, after all, what our hunter-gatherer ancestors would have eaten? Either way, it's as close as you'll get to a paleo diet in the 21st Century.
(1) Konner M, Eaton SB (2010) Paleolithic nutrition: twenty-five years later. Nutr Clin Pract. 25(6):594-602
(2) O'Keefe JH Jr and Cordain L (2004) Cardiovascular disease resulting from a diet and lifestyle at odds with our Paleolithic genome: how to become a 21st-century hunter-gatherer. Mayo Clinic Proceedings 79(1):101-8
(3) Lindeberg S, Jönsson T, Granfeldt Y, Borgstrand E, Soffman J, Sjöström K, Ahrén B (2007) A Palaeolithic diet improves glucose tolerance more than a Mediterranean-like diet in individuals with ischaemic heart disease. Diabetologia 50(9):1795-807
(4) Jönsson T, Granfeldt Y, Ahrén B, Branell UC, Pålsson G, Hansson A, Söderström M, Lindeberg S (2009) Beneficial effects of a Paleolithic diet on cardiovascular risk factors in type 2 diabetes: a randomized cross-over pilot study. Cardiovasc Diabetol 8:35
(5) Milton K (2000) Hunter-gatherer diets-a different perspective. Am J Clin Nutr ;71(3):665-7.