According to the abstract of Freese et al’s latest study, “returning to our Paleolithic roots may have positive effects on risk factors commonly associated with metabolic disorders.”
This conclusion is based on the data obtained from sending 13 healthy men and women into a National Park for 4 days and 3 nights. The goal was to return them to a “metaphorical paleolithic hunter-gatherer condition of living.” Accordingly, they lived and slept outdoors with no shelter.
And just like all other hunter-gatherer tribes before them, water was available every morning from a nearby holiday apartment. Food was also provided to the participants, including a morning ration of fruit, nuts, and tubers alongside instructions not to eat before noon, and “paleo meals” supplied at night.
At the end of the 4-day intervention, the participants showed significant reductions in fasting glucose (-18%), fasting insulin (-50%), and HOMA-IR (-58%; proxy for insulin resistance), as well as a marginally significant reduction in triglycerides (-18%). The researchers were also quick to point out the favorable effects on body composition, with reference given to the significant reductions in bodyweight (-3.9%), body fat mass (-7.5%), and visceral fat (-14.4%).
What isn’t mentioned is that 68% of the weight loss came from fat-free mass. The participants lost an average of 2.7 kg of bodyweight, of which only 0.87 kg was fat mass. The remainder came from water and muscle (more likely the former). Overall, body fat percentage was reduced from 16.6% to 16%.
And the paleo diet or “habitat” may have had nothing to do with it. These changes in weight are expected to occur when the food ration you provide to individuals averaging 15 km of hiking per day amounts to less than 1600 kcal. Specifically, this consisted of 24% protein (96 grams; 1.37 g/kg), 54% fat (94 grams), and 22% carbohydrates (86 grams). The percentage distributions were based on estimations made by Loren Cordain, indicating that these researchers must not have read my latest article on the foraging habits of hunter-gatherers.
What was the point of this research?
I have written extensively about paleo diet research. And the majority of it does support the findings of Freese et al in this current study. However, it saddens me to see such poorly conducted and controlled for research being published (and we wonder why the mainstream can’t take the paleo diet seriously). I suppose it should not come as a surprise, however, given that it was published in the Ancestral Health Society publication, Journal of Evolution and Health.
Anyway, this serves as a great example of research that must be scrutinized. Bias is obvious in the conclusions and the researchers didn’t correct for multiple comparisons in their statistical analyses, changed so many variables at one time that it is impossible to say which did what, and lacked a control group for comparison.
The one thing we can confidently take away from this research is not that returning people to an ancestral-like habitat improves health, but rather that subjecting people to high levels of physical activity and a relatively low caloric intake causes weight loss that is associated with improvements in glucose homeostasis. But we already knew this.