Okay, so as for why calorie restriction works. I looked it up on Wiki (http://en.wikipedia.org/wiki/Calorie_restriction) for now, and got a few theories: 1) (Mito)hormesis: Which apparently claims that less calories puts a little stress on the body, which is good. It restricts glycose metabolism and therefore increases oxydative stress, which causes the body to be better able to fight oxydative stress. So it helps fight oxydative stress by exposion and resistance. 2) Insulin signaling: "metabolism changed to reduce activity of the hormone insulin or downstream elements in its signal transduction, consequently retaining the leanness of animals in the earlier studies." I'm not actually sure whaat the first part says, but it seems to go on to say, "stay lean". So excess fat helps ageing, then. Get lean. 3) Sir2/SIRT1: Maybe a gene/enzyme, SIRT1, prevents cell death and releases fat from storage cells when you get less calories. It is, apparently, also released by some chemicals (reservatrol brought as an example), unless the gene is mutated. But CR may have nothing to do with sirt1. So an enzyme releases fat and preserves cells. Maybe reverts energy and nutrients to the cell. The enzyme then, can be activated by either CR or some other chemicals (reservatrol), if it's true. So try to get those enzymes to work. Drink red wine. 4) DHEA: a steroid prohormone, which is important and has something to do with sex. CR increased its production in some pre-pubecent primates. So... what? 5) Free radicals and glycation: Erm...I guess, less calories will mean mitochondria work better, produce less superoxide so there's less free radicals. And a lean body will require (a little bit) less energy (if you sit behind a computer, does it really matter?). It also compares II diabetics to fast ageing, due to being insensitive and tolerant to glycose. So... don't let your energy-producers get lazy, or they'll be ineffective. Or, if you give them too much food, they'll crap out too many free radicals - which appear to possibly be one of the main ageing factors. 6) Papers on CR in yeast: " ...calorie restriction decreased the activity of TOR, a nutrient-responsive signaling protein already known to regulate aging in worms and flies." A protein, which signals death? Death, TOR is thy name. And less food causes it to not work as well. So it's kind of a "eat yourself to death" countdown with maybe some other factors in play? I guess eating much may be "living fast". *shrug* Will have to look into TOR. If someone else posted about it, would be good, too... 7) Papers on CR in C. elegans: CR maybe increases respiration in C.elegans (a tiny worm). So... it causes better oxygen supply, or corrects it and makes oxygen go to the right place, or something... breathe well. 8) Evolution: During famine, it may be better for a body to not reproduce, but preserve what's already there. It's apparently regulated by hormones and CR should promote that "state" in the body. So... put your body on a "famine" mode. Not sure, but this may also demand "don't get kids". Anyone with more biochemistry knowledge or who's looked into the subject more thoroughly?
