Rabbit starvation

Rabbit starvation is the form of acute malnutrition caused by excess consumption of rabbit meat (and possibly other lean meats) coupled with a lack of other sources of nutrients. Symptoms include diarrhea, headache, lassitude, a vague discomfort and hunger that can only be satisfied by consumption of fat or carbohydrates.

Possible mechanisms

 * Lack of fats in the diet.
 * Rabbit being comparatively low in some amino acids that human beings cannot synthesize themselves.
 * Lean meat, being mostly protein, must be broken down into amino acids and then converted into glucose (via gluconeogenesis) in order to be used as an energy source. This process takes time, and can not be done quickly enough to meet the energy requirements of an active person. After the body's energy reserves (fat) are depleted, the energy requirements to sustain basic life processes are not met.
 * The ammonia released during the process of converting amino acids into glucose can not be cleared by conversion to urea quickly enough. The buildup of ammonia is poisonous.

Observations
Vilhjalmur Stefansson wrote as follows: "'The groups that depend on the 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 diarrhoea in about a week, with headache, lassitude and 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. Some think a man will die sooner if he eats continually of fat-free meat than if he eats nothing, but this is a belief on which sufficient evidence for a decision has not been gathered in the North. Deaths from rabbit-starvation, or from the eating of other skinny meat, are rare; for everyone understands the principle, and any possible preventive steps are naturally taken.'"

Charles Darwin, in The Voyage of the Beagle, wrote: "'We were here able to buy some biscuit. I had now been several days without tasting any thing besides meat: I did not at all dislike this new regimen; but I felt as if it would only have agreed with me with hard exercise. I have heard that patients in England, when desired to confine themselves exclusively to an animal diet, even with the hope of life before their eyes, have hardly been able to endure it. Yet the Gaucho in the Pampas, for months together, touches nothing but beef. But they eat, I observe, a very large proportion of fat, which is of a less animalized nature; and they particularly dislike dry meat, such as that of the Agouti. Dr. Richardson, also, has remarked, “that when people have fed for a long time solely upon lean animal food, the desire for fat becomes so insatiable, that they can consume a large quantity of unmixed and even oily fat without nausea:” this appears to me a curious physiological fact. It is, perhaps, from their meat regimen that the Gauchos, like other carnivorous animals, can abstain long from food. I was told that at Tandeel, some troops voluntarily pursued a party of Indians for three days, without eating or drinking.'"