Background: The observation that the emergence of common Western diseases takes place with much greater prevalence as societies migrate from natural-living cultures to modernized societies, has been well documented. For approximately 84,000 generations humans lived under hunter-gatherer conditions but recently endured dramatic change from our native lifestyle with the occurrence of the agricultural, industrial, and digital revolutions. The massive technological advancement that occurred within a relatively recent timeframe enabled humans to live in manner that is remarkably different than our pre-agricultural past. Consequently, the shift from a natural to a modern lifestyle likely promotes a gene-environment mismatch which causes metabolic dysregulation which causes disease.

Methods: Using a within-participant design, we examined whether, compared to baseline, changes in lifestyle towards a more Paleolithic-style pattern, for a four-day and four-night period related to changes in a variety of metabolic parameters. Two groups of 14 volunteers were isolated for a period of four days and four nights in the natural park Südeifel on the borders between Germany and Luxembourg. Participants lived outdoors without tents. The daily hiking performance was 16.4 km (≈ 24963 steps/day) and the daily activity time 5.49 h/day by a mean caloric intake of 1747 kcal/day.

Results: After four days of simulated Paleolithic conditions, body weight (-2.9%), body mass index (-2.7%), body fat (-10.4%), visceral fat (-13.6%) and waist-hip-ratio (-2.2%) significantly decreased, while muscle mass significantly increased (+2,3%). Additionally, fasting glucose (-6.5%), basal insulin (-44.4%), homeostasis model assessment-index (-49.3%) and fatty liver index (-41%) significantly dropped. In contrast, C-reactive protein, significantly increased (+67.1%).

Conclusion: Our study indicates that a short nature trip, where modern humans adjust their behavioral patterns to simulate a more Paleolithic-like condition, could serve as an effective strategy to help prevent or improve modern metabolic disease. Particularly, the major findings of an expeditious reduction of homeostasis model assessment-index and fatty liver index scores in only four days reveal the potential for meaningful benefits with such an intervention, even when compared to the effects of longer-term, single-intervention studies such as dietary or fitness programs on similar metabolic parameters.

On their way from the Stone Age via the Agricultural Revolution to current high-tech conditions, humans lost their primal foraging behavior. Today, energy expenditure is not necessary anymore for gathering nor hunting, and metabolic diseases are epidemically arising wherever our original Paleolithic lifestyle is turning into a modern sedentary lifestyle. In this pilot study, we followed through the concept that a radical change towards a Paleolithic hunter-gatherer lifestyle could serve as therapy against any metaflammatory disease, even in the short term. Thirteen healthy adult volunteers were transferred to the DELUX National Park (Germany and Luxembourg) for four days and three nights, where Stone Age conditions where mimicked. Thirty-eight biochemical and bioelectrical parameters were measured from participants before and after this relocation. Body weight (-3,9%), body fat (-7,5%), body mass index (-3,8%), visceral fat area (-14,4%) and metaflammation-related parameters (fasting glucose = -18,2%; fasting insulin = -50,1%; HOMA = -57,8%) decreased significantly. C-reactive protein, as the main indicator for low-grade inflammation, increased up to an average of 169,6 %. Our data show that returning to our Paleolithic roots may have positive effects on risk factors commonly associated with metabolic disorders, such as obesity and type 2 diabetes. These findings may lead the way to further research to answer the question whether the already existing metabolic conditions and/or autoimmune and neuroinflammatory diseases could be influenced by a Paleolithic lifestyle.