I recall reading about some of the military survival training, that some of the desert (spell check - dry places, not sweet after-dinner edibles) rabbits were so lean that a human just could not survive on them. They thought they were getting sufficient calories, their stomachs were full, but the fat content was so low that they ended up 'starving'?
-ERD50
I think there is some truth to this. Found this online:
"Rabbit Starvation"
The name "rabbit starvation" may have been coined by an arctic explorer by the name of
Vilhjalmur Stefansson, who spent many years in the early 1900's living with the Eskimos and Inuits of Alaska and Northern Canada.
Mr. Stefansson wrote,
"The groups that depend on blubber animals are the most fortunate in the hunting way of life, for they never suffer from fat-hunger. This trouble is worst, so far as North America is concerned, among those forest Indians who depend at times on rabbits, the leanest animal in the North, and who develop the extreme fat-hunger known as rabbit-starvation.
"Rabbit eaters, if they have no fat from another source - beaver, moose, fish - will develop diarrhea in about a week, with headache, lassitude, a vague discomfort. If there are enough rabbits, the people eat till their stomachs
are distended; but no matter how much they eat they feel unsatisfied."
Carbohydrates are formed from carbon, hydrogen and oxygen. Fats are formed from the same three components.
However, to form proteins, the body must add nitrogen and other nutrients to these three building blocks.
Your body normally burns fats as energy, and your brain burns glucose, a sugar. The body CAN burn protein, but it is not a healthy long-term solution. Protein, when broken down, forms ammonia and other by-products which the body has to cleanse away, straining the liver and kidneys.
The amino acids from protein are converted into glucose by the liver. The process is complex and requires a large amount of energy. ATP (energy molecules) are used to convert amino acids to glucose, and even more are then required to convert the harmful protein byproduct ammonia into urea which is flushed away by the kidneys.
Here's the problem: the body can only supply roughly 1000 calories per day through a protein-only diet because the liver is only capable of producing 250 grams of glucose from protein, no matter how much protein you eat. So, you will still feel hungry, and you'll eat more. Unfortunately, your liver will start struggling and failing to convert the ammonia into urea (not enough ATP) so the ammonia will reenter your blood stream. This starts messing with your nervous system.
According to the
Back Across the Line blog,
"Excess intake of nitrogen leads in a short space of time to hyperammonemia, which is a build up of ammonia in the bloodstream. This is toxic to the brain. Many human cultures survive on a purely animal product diet, but only if it is high in fat.
"A lean meat diet, on the other hand cannot be tolerated; it leads to nausea in as little as three days, symptoms of starvation and ketosis in a week to ten days, severe debilitation in twelve days and possibly death in just a few weeks. A high-fat diet, however, is completely healthy for a lifetime.