These arguments are not logically coherent.
The fact that the human body evolved to deal with the possibility of periodically occurring period of hypocaloric nutrition (or even fasting) does not necessary mean they are ideal or necessary for it to function optimally. Similarly, it is quite possible that, during the human evolution, human populations had access to different food sources in different times of the year and at different times of the year may well have had limited amounts of some micronutrient or other; the fact that the body evolved to cope with this natural variability doesn't logically dictate that it is necessarily healthier than having a non-variable but micronutrient-complete diet year-round.
The argument that if the world had no pathogens you would be less healthy also doesn't follow as a necessary logical conclusion. Exposure to pathogens is preferable because it is necessary to develop your immune system to deal with the pathogens you may come in contact with in the future. In analogy to your "variability in diet" argument where you suggested living in a world where you could have an "ideal" diet year-round is lacking variability and would thus be somehow detrimental, if we lived in a world with no pathogens irl then exposure to pathogens wouldn't necessarily promote good health/proper physiological function. Also, where did you get the idea that allergens are beneficial for your health?
The similar line of thought about the "cancer in modern society as well as in zoos" falls to same same logical culprits. You are blaming the lack of diet variability, when there are so many other strong factors negatively affecting the normal physiological function (lack of normal activity patterns that are necessary for proper gene expression and physiological function, shitty food quality, psychological stressors, chemical stressors...). You are basically suggesting that if the zoo animals were fed with an intermittent fasting protocol according to "natural variation" that would improve their cancer rates. That's a baseless assertion as far as I'm concerned.
It's good to have you back, btw! :icon_chee
It wouldn't be a welcome wagon without a thorough post from maiou!
My argument about variability comes from complex systems analysis. Variability being a precursor for robustness is based on mathematical models and natural observations. It applies not just to biological complex systems, but to economics, politics, moral development and a wide range of subjects. I adopted this from an economist, Nassim Taleb. I felt it is a good, simplistic representation of how biological systems become strong. It also falls along the definition of health used by some people - that health is a gradient, represented by the difference between the most you can do and the least you can do. Sounds vague and hippy-ish but sometimes that's how people get exposed to a different way of looking at the problem.
The pathogens and allergens stuff was just said tongue in cheek, so I'll skip over that and jump to the zoo comment.
I never denied that there were more problems than just feed timing with zoo animals. It's just one issue among many (namely longer lifespan from medical care). If you're looking for practical studies about CR and IF reducing cancer rates, look no further. There's already a huge body of evidence showing the benefits of CR for cancer prevention, so I'll just post links to a few about IF, since there aren't that many yet.
Adult-onset calorie restriction and fasting delay spontaneous tumorigenesis in p53-deficient mice
Effects of caloric restriction on cell proliferation in several tissues in mice: role of intermittent feeding
Weight-cycling decreases in... [Cancer Epidemiol Biomarkers Prev. 2002] - PubMed - NCBI
Further, this just takes some knowledge on the cellular processes that occur while feeding. All feeding stimulates cancerous pathways and suppresses tumor inhibitors temporarily. Insulin, and other growth factors released during feeding, explicitly activate growth pathways and shut off DNA repair/apoptotic mechanisms.
Here's a list of pro-cancerous molecules that are upregulated through feeding:
Akt, PKA, CREB, mTor, Adenyl Cyclase, RAS, Bcl-2, CDK2
Those same molecules also inhibit anti-cancerous molecules (and vice versa):
p53, AMPk, Cytochrome C, Caspases, FOXO
There are two states: Cell growth and cell death/repair. Both are essential, but by constantly feeding, or feeding too much, you inhibit one side of that coin (the anti-cancer side). Likewise, by not feeding often enough or feeding too little you inhibit important growth processes and over-express molecules that promote cell death. I hope this post cleared up some questions.
