Cutting Meat And Dairy For Just a Few Weeks Can Alter Your Body’s Chemistry
Health14 August 2026ByJess Cockerill
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We know that plant-based diets can be a good option for people looking to improve their health, and a new study based on real-world dietary practices reveals fresh insights on why that might be the case
The study followed a group of 200 healthy people from the greater region of Thessaloniki, Greece, who abstain from meat, fish, dairy and eggs (essentially taking on a vegan diet) for a total of 180-200 days each year, as part of a religious practice connected to Orthodox Christianity
These Orthodox Christians undertake this form of fasting on Wednesdays and Fridays every week, as well as across four longer periods through the year
That includes the 40 days preceding Christmas; 48 days preceding Easter (Lent); from 8 to 42 days during what is known as the Apostles’ Fast or the Fast of Peter and Paul; and for 15 days in August, for the Assumption of the Virgin Mary
“This dietary regime is a real-world dietary pattern that is strongly motivated by religious belief, and is typically part of the culture of the family practicing individuals are born into,” explain biostatistician Alexandros Simistiras and colleagues in a paper published in Nature Communications
“Typically, during animal product restriction, in addition to a pronounced reduction of animal fat intake, periodically restricted individuals undergo restriction of protein (as a proportion of total energy intake). This is driven by abstinence from almost alln total energy intake.”
As far as the scientists are concerned, this religious tradition creates a pretty ideal natural experiment for seeing how gene activity changes with diet
“The consistency of this dietary pattern and the predictability of the shift between omnivory and animal product restriction render this study comparable to a dietary intervention study,” Simistiras and team point out
For a comparison group, the researchers enlisted 211 participants from the same area who do not observe these dietary restrictions
What they found were several important changes to the body’s chemistry – particularly certain levels of gene expression
The researchers already knew the Orthodox tradition of switching to mainly plant-based foods led to “extensive metabolic reprogramming, with mostly beneficial effects on health, including …altered abundance of key immunometabolic proteins, including potent metabolic hormone FGF21″
The new study revealed that participants practicing the meat-free fasts, who also had a certain gene variant that adjusts levels of the FGF21 protein, showed physiological signs the researchers think may be associated with a process known as adipose tissue beiging, which is when energy-storing white fat cells act a lot more like the brown fat cells that are readily burned to create heat
“Although these findings should be interpreted with caution, it is plausible that diet-induced FGF21 levels may influence the process of adipose tissue beiging in humans,” the authors write
A certain gene variant that is involved in regulating a protein called LBR (essential for the biosynthesis of cholesterol) was also affected by giving up meat, in just a few weeks
That same gene variant also seemed to come with another effect linked to obesity
“This genotype-dependent upregulation of LBR may be a compensatory response to reduced dietary intake of cholesterol during animal product restriction compared to omnivory,” the authors note
This hints at just how complicated the interplay of diet and genetics is when it comes to obesity
“Carriers may be slightly more protected against obesity through the action of LBR, when practicing dietary restriction,” the authors explain
“This finding may contribute to our understanding of why individuals who follow similar dietary patterns may exhibit differential risk for obesity and provides broader insight into mechanisms shaping diet-dependent differences in <a href="https://healthylife7.com/dr-ed-dominguez-addresses-flesh-eating-bacteria-blood-pressure-meds-and-heart-disease-risk/” title=”Dr. Ed Dominguez addresses flesh-eating bacteria, blood pressure meds and heart disease risk”>disease risk.”
Ultimately, the study reveals many starting points for further research into the complex interplay of diet, genetics, and metabolic conditions
Even just a few weeks of cutting meat and dairy, it appears, can make a big difference
The research was published in Nature Communications
This article was fact-checked by Fiona MacDonald and edited by Peter Dockrill. While we pride ourselves on our process, we are only human. If you spot a mistake, please let us know
