Vilhjalmur Stefansson and the Bellevue Experiment

In February 1928, two men checked into Bellevue Hospital in New York City to begin one of the strangest nutrition experiments of the twentieth century. For the next year they would eat nothing but meat, fat and organs, under the watch of a committee of respected scientists. Nearly a century later, it remains the most carefully documented long-term all-meat diet on record.

Who was Vilhjalmur Stefansson?

Vilhjalmur Stefansson (1879 to 1962) was a Canadian-born explorer and ethnologist of Icelandic descent. Between 1906 and 1918 he spent long periods in the Canadian Arctic, living with Inuit communities and adopting their way of life, including a diet that for months at a time consisted almost entirely of meat and fish.

He returned convinced that this diet had kept him healthy and energetic, and that common beliefs about the dangers of an all-meat diet (scurvy, kidney damage, "hardening of the arteries") were wrong. Many physicians were sceptical. Stefansson proposed a test.

His partner in the experiment was Karsten Andersen, a Danish member of one of his Arctic expeditions, who had also lived on a meat diet in the north.

How the experiment was set up

The study was overseen by a committee of scientists from institutions including the Russell Sage Institute of Pathology, and conducted in part at Bellevue Hospital. The plan was:

An initial period on a mixed diet in the hospital for baseline measurements.
A period of close observation in the metabolic ward after switching to an all-meat diet, where everything eaten and excreted could be measured.
The remainder of the year living normally in the community, eating only meat, with regular check-ups and tests.

The diet included beef, lamb, veal, pork, chicken, organ meats, bacon, fish, and fat. Fruit, vegetables and grains were excluded.

The lean meat episode

One of the most instructive moments came early. Stefansson later wrote that the investigators, wanting to test a diet higher in protein and lower in fat, gave him lean meat. Within a few days he developed nausea, diarrhea and a general feeling of illness, which he recognised from his Arctic experience of eating lean meat without enough fat. When fat was restored, he recovered^[1].

This is Stefansson's own account rather than a controlled observation, but it matches what Arctic peoples and later observers reported, and it is why modern carnivore eaters are advised to eat fatty cuts rather than lean meat alone.

What they ate

For most of the year, the men ate as much as they wanted of fatty meat. The detailed metabolic reports found that the diet was high in fat, with protein making up a minority of calories, far from the lean, protein-heavy image many people have of an "all-meat" diet^[2].

What was measured, and what was found

The results were published in several scientific papers. The two most cited are:

McClellan and Du Bois (1930), Journal of Biological Chemistry. This paper examined kidney function and ketosis over the year. The investigators found no evidence of kidney damage, and both men showed mild, continuous ketosis on the meat diet^[2].
Lieb (1929), JAMA. This clinical report described the health of the two men throughout the year and concluded that they remained in good health, with no signs of the deficiencies or damage that critics had predicted^[3].

Neither man developed scurvy. Neither showed obvious signs of vitamin deficiency. Both reported feeling well.

Stefansson later wrote a popular account of his dietary experiences, "Adventures in Diet", published in three parts in Harper's Monthly Magazine in 1935 and 1936^[4]^[5]^[6]. These essays are engaging and influential, but they are his personal interpretation, not the scientific record.

What the experiment shows

Two healthy adult men lived for a year on an all-animal diet, including organ meats and ample fat, without detectable harm to kidney function and without scurvy.
Fat intake is critical: lean meat alone was poorly tolerated.
Many of the dire short-term predictions of the day did not come true.

What it does not show

It was two people. Both were healthy, active men who had already lived on meat diets. Results for women, older adults, children, or people with health conditions cannot be inferred.
It lasted one year. Heart disease, cancer and many chronic conditions develop over decades.
The methods of the 1920s were limited. Modern markers such as ApoB, detailed micronutrient status, gut microbiome analysis, and coronary imaging did not exist.
There was no control group eating a different diet under the same observation.

Stefansson's later life

Stefansson lived to 82, dying in 1962. He continued to advocate for high-fat, low-carbohydrate diets throughout his life. It is sometimes claimed that he ate an all-meat diet for most of his later life; the reality is that his diet varied, and no single anecdote about one long-lived person tells us much about a diet's effect on longevity.

Why it still matters

The Bellevue experiment remains important because it was a serious attempt to test a controversial idea with the best tools available. It moved the conversation from speculation to observation. Modern researchers who want to understand the carnivore diet should aim for the same spirit: careful measurement, honest reporting, and appropriate humility about what a single study can prove.

The full text of "Adventures in Diet" is available through the Internet Archive for anyone who wants to read Stefansson's own words^[1].