The Paleo diet prompts us to mimic the food choices of our prehistoric ancestors. In practice, this means avoiding dairy products, grains, legumes and processed sugar and instead consuming vegetables, fruits, nuts, pasture-raised meats and wild-caught fish.
Proponents of the paleo diet argue that by eating this way we will lose weight and reduce the risk of chronic disease.
The Paleo Diet’s roots go back to the 1950s, but it owes its current popularity to a book by Loren Cordain titled The Paleo Diet: Lose weight and become healthy by eating the food you were designed to eatwhose first edition was published in 2001.
In the 22 years since Cordain’s book was published, the Paleo diet has been adopted by several million people and a multibillion-dollar industry has grown around it, including premium foods and a certification system.
The health claims of the paleo diet
A multibillion-dollar industry has developed in connection with the paleo diet, including premium priced foods and a certification scheme.(Amalea Ruffett), Author provided
While the Paleo diet has many adherents, clinical research has yet to substantiate its purported health benefits.
For starters, it doesn’t seem to outperform conventional recommended diets as a means of medium to long-term weight loss. The only published multi-year study evaluating the impact of the paleo diet on weight loss found that following the paleo diet was no more effective than following the official nutritional recommendations of the Nordic countries after two years.
It’s a similar story with the claims that have been made about the impact of the paleo diet on chronic disease. For example, a recent review found that studies examining the impact of the paleo diet on type 2 diabetes were “inconclusive.”
Similarly, the authors of a 2020 study reported that following the paleo diet led to a higher relative abundance of gut bacteria that produce a chemical associated with cardiovascular disease, which runs counter to the claim that the paleo diet it will reduce the likelihood of suffering from chronic diseases.
Why aren’t the claimed health benefits of the paleo diet supported by clinical research? As evolutionary anthropologists, we think the problem is that the Paleo Diet is based on an incorrect premise and incorrect data, and in what follows we will try to show why our research has led us to this conclusion.
An incorrect premise
The idea behind the Paleo Diet is that the current rise in obesity and associated diseases in many countries is the result of a mismatch between the foods we eat and the foods our species has evolved to consume.
This discrepancy, the argument goes, is a consequence of the fact that too little time has passed since agriculture appeared 12,000 years ago for evolution to have adapted our species to cope with a high-carbohydrate diet. and low in protein or to process domesticated food. .
This argument seems reasonable because there is a perception that evolution is a very slow process. However, it’s not actually supported by research on diet-related genes.
Work on lactase persistence, the continued ability to produce the enzyme lactase as an adult, illustrates this. Lactase allows us to digest lactose, the sugar in milk, so the persistence of lactase is useful for a diet that includes dairy products. Lactase persistence is found in a few regions, one of which is Europe. Ancient DNA research indicates that lactase persistence is less than 5,000 years old in Europe.
Similarly, an analysis of genetic data from African populations published last year found evidence of a recent adaptation in a family of genes linked to alcohol metabolism. In this case, natural selection has been operating for the past 2,000 years.
This evidence shows that the discrepancy rationale for adopting the paleo diet is not supported by genetic studies. Such studies show that evolution can produce diet-related adaptations in much less time than has been the case since agriculture appeared.
Wrong data
There is also an issue with the Paleo Diet’s recommendations regarding the contribution of the three macronutrients protein, carbohydrate and fat to a person’s diet.
According to the current version of the Paleo Diet, we should aim for a diet that is 19 to 35% protein, 22 to 40% carbohydrates, and 28 to 58% fat, in terms of energy. This makes the Paleo Diet lower in carbohydrates and higher in protein than conventional recommended diets, such as those promoted by Health Canada and the United States Department of Agriculture.
The Paleo Diet’s recommended macronutrient ranges are based on a 2000 study that estimated macronutrient percentages for more than 200 hunter-gatherer groups. However, we recently discovered that there is a problem with this study.
The problem lies in the macronutrient values that the researchers used for plant foods. Although they used different sets of macronutrient values for animal foods, they only used one set of macronutrient values for plant foods. They obtained the plant data from an analysis of foods traditionally eaten by Indigenous Australians.
In our study, we evaluated the effects of this decision with two plant macronutrient datasets, both consisting of values for plants consumed by hunter-gatherers from different continents.
Using multicontinental plant data resulted in significantly different macronutrient estimates. These in turn produced wider ranges of macronutrients than those recommended by the Paleo Diet. The ranges we calculated are 14 to 35% protein, 21 to 55% carbohydrates, and 12 to 58% fat, for energy.
These ranges overlap with those recommended by Health Canada (10 to 35% protein, 45 to 65% carbohydrates, and 20 to 35% fat) and the United States Department of Agriculture (10 to 30% of protein, 45 to 65% carbohydrates and 25 to 35% fat).
The fact that the macronutrient ranges of hunter-gatherer diets overlap with government-approved macronutrient ranges challenges the notion that the Paleo diet is healthier than conventional recommended diets.
It’s time to leave the paleo diet in the past
Given that the rationale for adopting the Paleo Diet isn’t supported by available scientific research, and its macronutrient recommendations aren’t scientifically sound, we suggest it’s no surprise that the diet’s purported health benefits haven’t been backed up by clinical trials.
The Paleo diet was a worthwhile experiment, but at this point it seems likely that people who follow it are simply wasting money. Government-recommended conventional diets offer comparable results at a lower cost. In our opinion, it’s time to leave the Paleo diet in the past.
Mark Collard, Canadian Research Chair in Human Evolutionary Studies and Professor of Archaeology, Simon Fraser University and Amalea Ruffett, PhD Student in Archaeology, Simon Fraser University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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