This blog post reveals a truly wild chapter in nutritional history: a year-long, medically supervised all-meat diet experiment… conducted in the 1920s by an Arctic explorer who lived with the Inuit. This is one of the earliest ‘carnivore diet’ experiments ever documented — and yet, shockingly, most modern nutrition science completely overlooks it. Let’s unpack what actually happened, who was involved, and what we can learn.
First — who was this explorer? Vilhjalmur Stefansson was a Canadian-born Arctic explorer and ethnologist, born in 1879. He spent more than a decade living with Inuit communities, learning their language, culture, and, perhaps most interestingly, their diet. During his expeditions, Stefansson observed that Inuit diets were overwhelmingly meat and fat — seal, whale, caribou, and fish — with very little plant intake. He believed that Europeans and Americans had wrongly assumed that humans needed carbohydrates or vegetables to stay healthy, and he became determined to challenge that belief scientifically. That’s a bold claim — especially in the 1920s, when vitamins like vitamin C were just being discovered, and scurvy was still a major concern.
To silence his critics, in 1928 Stefansson, along with fellow explorer Karsten Anderson, entered Bellevue Hospital in New York City for a controlled dietary experiment. Under direct medical supervision, they committed to eating only meat and water for an entire year. The diet wasn't just steaks and roasts; it included a broad range of animal foods like organ meats, brain, tongue, calf liver, and fatty cuts. Their macronutrient intake worked out to roughly seventy-five to eighty-five percent fat, fifteen to twenty percent protein, and only trace carbohydrates that came from glycogen naturally found in meat. Think about that for a moment: nearly every calorie came from meat and fat, for a full year, under clinical observation.
The results were eventually published across several scientific papers. Clarence W. Lieb documented the experiment in a JAMA article titled ‘The Effects on Human Beings of a Twelve Months' Exclusive Meat Diet.’ Later, in 1930, Walter S. McClellan and Eugene F. Du Bois published a more detailed analysis called ‘Prolonged Meat Diets with a Study of Kidney Function and Ketosis’ in the Journal of Biological Chemistry.
Doctors reported that both men stayed mentally alert, physically active, and showed no signs of nutritional deficiency. Stefansson lost a small amount of weight early on, but his weight normalized as his calorie intake fluctuated between about two-thousand and thirty-one-hundred calories per day. Kidney function was closely monitored throughout the experiment, and physicians found no evidence of kidney damage after the year was complete. Their urine acidity did increase, which is expected on a diet high in protein and low in carbohydrates, and they remained in ketosis consistently throughout the trial. Stefansson entered the study with mild gingivitis, but by the end of the experiment his gums had healed, suggesting he did not suffer scurvy despite consuming no fruits or vegetables. In short, from a clinical standpoint, both men appeared to thrive on a strict meat-and-water diet for a full year. That doesn’t mean the diet was perfect or universally recommended — but the results were far more successful than critics predicted at the time.
So why is this study barely mentioned in mainstream nutrition today, despite being so groundbreaking? One reason is funding bias — part of the study’s support came from the Institute of American Meat Packers, which has led some researchers to dismiss it. Another reason is that nutrition science in the 1920s was rapidly shifting toward vitamin theory and an emphasis on fruits and vegetables as necessary for preventing disease, so this experiment challenged the emerging paradigm rather than fitting cleanly into it. The sample size also worked against its legacy — with only two participants, modern scientists often view it as too small to take seriously. There’s also a cultural factor: modern nutrition research favors randomized controlled trials and large datasets, whereas this experiment was more of a supervised self-test conducted by explorers. And finally, some argue the findings may not translate perfectly to the general population because Inuit populations historically have genetic adaptations that help them metabolize high-fat diets efficiently.
So what does this forgotten 1928 study mean today in a world where keto and carnivore diets are becoming increasingly popular? The experiment provides a compelling proof of concept that a zero-carb, meat-only diet can be sustained for long periods without obvious short-term harm in healthy adults. It also shows that long-term ketosis is possible and not inherently pathological. The experiment highlights the importance of using a full spectrum of animal foods — including organs and fat — to provide nutrients that might otherwise be lacking. And perhaps most importantly, the experiment illustrates a gap in how modern nutrition treats historical evidence, since this real clinical trial is rarely discussed even when the topic turns to low-carb or animal-based diets. Of course, none of this automatically proves the diet is optimal for everyone, because lifestyle, genetics, and broader health context matter a lot.
So, to wrap this up: In the late 1920s, Vilhjalmur Stefansson — an Arctic explorer who lived among Inuit communities — and his colleague committed to eating only meat under strict medical supervision at Bellevue Hospital. They finished the year in strong health, in ketosis, and without the expected issues like scurvy or kidney damage. Yet today, this experiment is rarely acknowledged in mainstream nutrition. Whether or not you think a carnivore-style diet is optimal, this study remains a fascinating historical challenge to long-held dietary assumptions. If you enjoyed this dive into nutritional history, be sure to drop a comment below and share your thoughts. Could a diet like this really work long-term, or is it just a historical curiosity? Thanks for your interest.
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