Comment by jasonkolb | Hacker News Reader

Comment by jasonkolb | Hacker News Reader

Caloric restriction is absolutely fascinating in all forms. I think intermittent fasting might be the best-known variant of this, but there are others. All of them cause dramatic changes in the way bodies function, from changing the hormones secreted to changing the form of fuel it uses to run itself (e.g. ketones in low-carb diets instead of glucose).

Caloric restriction has a whole bunch of knock-on effects, any one of which could have a huge impact on health and aging. For example, restricting calories means that you're restricting protein. Most people think of protein as a good thing, but that's what stimulates the hormone IGF-1 to be secreted, which is necessary for growth of all kinds--muscle growth (which is why bodybuilders eat as much protein as possible), but also including cancer.

I've seen research that suggests that cells don't go into "repair mode" in the presence of IGF-1. This is just one example of a possible mechanism that caloric restriction could have a hugely beneficial effect on aging and illness in general.

I have a half-written blog post about this I should push out. I'd love to get some more conversation going around this.

>For example, restricting calories means that you're restricting protein. Most people think of protein as a good thing, but that's what stimulates the hormone IGF-1 to be secreted, which is necessary for growth of all kinds--muscle growth (which is why bodybuilders eat as much protein as possible), but also including cancer.

While people on CR do seem to try and keep IGF-1 on the lower side, there's no consensus on protein yet. Most seem to eat a normal proportion, (though still less than average person since their overall intake it lower.).

I have seen some people doing CR specially avoid whey protein because it's known to particularly raise IGF-1 (which is why on the other hand people trying to maximize size of muscles like it)

Ok, I think most of you who read PROTEIN, may misunderstand a bit here, I'll add a bit of info to clarify the protein debate a bit.

There are almost indefinite combinations of proteins, many of which have vastly different effects on the body and it's cells. To shed a bit of light on proteins, you should know that most enzymes are proteins too http://en.wikipedia.org/wiki/Enzyme

Some forms of 'proteins' may increase cancerous growth, other may inhibit it and there are many of such activators/inhibitors, just so you know. Only take a look at http://en.wikipedia.org/wiki/Myosin which there are proteins ("enzymes"), which may inhibit it, leading to a super-muscular body. It's a very small change, but the result is not what you would expect from just a protein. The contrary is true too, it could have damaging effect too. We are NOT talking about supplements here, but the form of proteins that occur in Nature. They are by far not researched enough to give any form of advice and there are still new breakthroughs, findings and surprises made in the area.

Roughly saying that no calories means, more lifetime, is like saying that not fueling a motor will increase it's lifetime.

Human Life is not about getting as old as possible anyway. My personal opinion is that it's there to bring healthy and smart kids to the world, which help in the betterment of the world with their creativity, skills, ideas, muscles, efforts and visions. Simple as that.

Most people think of protein as a good thing, but <that's> what stimulates the hormone IGF-1 to be secreted, which is necessary for growth of all kinds

When you say "that's" are you referring protein and specifically its presence or absence? It would be interesting indeed to see more research on this as well if possible dimensionalize by not only retsricted/normal kCal but at variations in % kCal by proteing etc. It would also perhaps be very interesting to understand if the variations align as mean values above and below "normal" caloric restricion. Ie, imagine a polar explorer who is operating in caloric deficit yet at high exertion thresholds for days on end. And/or contrast this with caloric restriction in the sense of < normal 2200 per day (or whatevs).

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