Proteins are emblematic of nutrition in our minds. We often commend foods have abundant vitamins and proteins, yet seldom mention their carbohydrates or fats that is notorious in contemporary perception. However, an extremely different world was unveiled by Vilhjalmur Stefansson in his Arctic expedition. Why is it impossible to sustain a healthy life solely on proteins? What critical role do fats play in our diet? Where do vitamins in a purely carnivorous diet come from?
Pure carnivorous Inuit food
A Canadian of Icelandic descent, Vilhjalmur Stefansson was an illustrious explorer and anthropologist that lived between 1879 and 1962. He was believed to be perhaps the first person of European descendant to contact with indigenous Inuit in Arctic. He also gained fame from his ketogenic diet advocacy. On the other hand, a severe criticism hit him due to abandoning his companions on the Karluk in 1913. Stefansson became separated from his expedition team, as well as his supplies in the winter of 1906-1907. Fortunately, a group of Inuit living in Canada's Mackenzie Delta found and took him in. He lived with them for a full 18 months during which he learned and completely adopted the Inuit way of life. Wild animals became his staple food. Caribou, seals, or whales were his only food for the long winter months. Salmon was reserved as the last food supply for the most challenging times. In spring, he consumed seagull eggs for a month. Berries could barely be enjoyed in the brief summer. It’s astonishing that he not only avoided malnutrition but also vigorous and in excellent health, despite virtually no vegetables and fruits.
Vilhjalmur Stefansson and Native Americans
However, he had a starkly different experience when he visited Native Americans in North America. Despite their excellent hunting skills, they had to rely on rabbits during the off-season. Stefansson experienced fatigue, headaches that followed by diarrhea. A condition that also afflicted the Native Americans. These symptoms only improved when American Indians hunted caribou and insisted he consume some fat. He learned that if other prey wasn’t accessible timely, people could die within weeks.
Stefansson’s Extreme Experiment
In 1928, he conducted an extreme experiment to prove that a pure carnivorous diet was harmless. He and a friend checked into Bellevue Hospital in New York, where they ate merely meat and water for a year. Proteins made up about 20% of his daily calories. The remaining calories came from fats. Doctors performed various tests on them, but they showed no signs of physical discomfort.
The Importance of Fat in Food: Rabbit Starvation
In his writings, Stefansson documented his various Arctic expeditions. He realized that certain symptoms were not coincidental but were direct results of an unbalanced diet. He coined the term "Rabbit Starvation" due to its association with rabbit meat; it is essentially a form of protein poisoning.
Glucose is hydrolysis product of carbohydrates and primary fuel for cells. When it is insufficient, fats are broken down into fatty acids and glycerol to maintain cellular operations. The Inuit's main food source is seal and salmon. Fats and proteins account for about 20% respectively, while carbohydrates and lactic acid make up only 1-2% (glycogen in animals rapidly decomposes into pyruvate and lactic acid in anaerobic fermentation after death). Thus, fats are primary energy source for the Inuit.
Modern Arctic expeditions carry ample citrus fruits to mitigate the risk of scurvy. How did the carnivorous Inuit avoid it? The answer lies in raw diet. When cooked, vitamin C is oxidized and lost. If you eat raw or lightly cooked meat, this problem is avoided. Although it has barely a little of vitamin C, it is sufficient to prevent scurvy.
However, the diet of Native Americans presented some issues. Rabbits contain only about 2-3% fat and 1-2% saccharide. Such a meager amount is clearly insufficient to sustain life. Consequently, amino acids are synthesized into glucose and ketone bodies for energy, but this also results in toxic ammonia from amino transfer. The energy obtained from amino acids can’t exceed 35% daily calories due to the liver's limited detoxification. This means that about 1250g of lean meat is the maximum amount an adult could intake a day. Consuming more increases metabolic strain, and nervous system may be damaged by the ammonia.