This is actually a poor way of estimating protein requirements because it completely ignores how the protein intake affects metabolic functions, like the synthesis and degradation of essential proteins. The most common method of estimating protein requirements in adults is the nitrogen balance method, which is when researchers find the amount of protein necessary to make sure the rats (or people, or other animals) are not excreting more nitrogen than they are consuming in their diets. While it is simple to determine the amount of protein that maximizes the growth of young rats, maximal growth does not necessarily mean maximal health, as Campbell frequently points out. As we will see below, this is exactly the case.Įstimating protein requirements is extremely difficult. The question is whether the same low-protein diets that prevent the growth of pre-cancerous lesions once they are formed also increase the toxicity of aflatoxin and other harmful chemicals, decrease the capacity for tissue repair, increase the risk of dying from chemical overdose, and promote the formation of pre-cancerous lesions when these diets are fed to the rats of the same strain, sex, age, and protein requirements. The question here, however, is not whether rats eventually grow to an age where they can tolerate low-protein diets. The younger the rats are, moreover, the more rapidly they are growing, so the effects on growth will be worst when the deficient diets are fed to weanling rats. I certainly agree that protein-deficient diets will only cause stunted growth when they are fed to growing rats. In any case this oversight of MJ’s is quite misleading. So no wonder the weanlings were having problems on a 5% protein diet, they really were protein deficient! This would also explain the case of weanling rats successfully blocking aflatoxin initiation fed 20% protein, they were being fed an adequate amount of protein for their age, and hence were better at fighting off disease than their protein-starved counterparts. Indeed rat mother’s milk contains 20% calories from protein vs. MJ neglects to mention that although adult rats and humans have similar protein requirements calorically (~5%), rats have considerably higher protein requirements when nursing and as weanlings (~20%), the latter being a period of rapid bodily growth. Based on the studies I was able to access and what I could gather the abstracts of others, it seems for the most part the rats having problems MJ attributes to ‘protein deficiency’ (stunted growth, increased susceptibility to aflatoxin poisoning etc.) were weanlings. Re: Masterjohn’s (MJ) article, since I do not have access to many of the articles he cites, at the moment I cannot assess how accurately he describes all of them. The response can be found here, and I will quote the relevant portion in full: Several readers forwarded me a response to my post “The Curious Case of Campbell’s Rats” that had been posted on the vegetarian site, 30 Bananas a Day!, and suggested I make a rebuttal. Nourishing Traditional Diets with Sally Fallon Morell.The typical dire rat is 2 feet long and weighs 25 pounds (2 bulk). The bite of these creatures will often carry a crippling disease. They are much larger than a common rat and are found in starship cargo bays and city sewers. While wild rats are seen as vicious and diseasecarrying beasts, tame rats are quite docile and friendly.ĭire rats are dangerous creatures. Rats thrive in urban environments, where they can easily feed off the leftover food and waste of the community. They are longtailed rodents that are considered pests wherever they exist. Skills Athletics +7, Stealth +7, Survival +3 Str +0 Dex +3 Con +1 Int -4 Wis +0 Cha +0 Offensive Abilities disease ( filth fever, DC 8) Init +3 Senses blindsense (scent) 30 ft., low-light vision Perception +3
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