Here is an interesting article:
Differences Between People And Animals On Calorie Restriction
I think I'll stick to IF
Differences Between People And Animals On Calorie Restriction
ScienceDaily (Sep. 24, 2008) — Calorie restriction, a diet that is low in calories and high in nutrition, may not be as effective at extending life in people as it is in rodents, according to scientists at Washington University School of Medicine in St. Louis.
I think I'll stick to IF
Comments
http://www.sciencedaily.com/releases/2008/05/080514064921.htm
"When It Comes To Living Longer, It's Better To Go Hungry Than Go Running, Mouse Study Suggests"
there's this bit in the middle;
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Rats that exercise regularly will, on average, live longer compared to a group that eats the same amount but does not exercise. This is because exercise prevents some diseases, which allows more individual animals to live out their expected life span.
However, when comparing the rats in these two groups that eat the same amount, the longest-lived animals in the exercise group don’t live any longer than the longest-lived rats in the non-exercise group. Taken together, these findings indicate that exercise can prevent an early death from disease in some rats, but does not extend the maximal lifespan of any of the rats.
When comparing rats that exercise to those that don’t exercise but eat much less, the longest-lived rats are from the group that ate less.
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At a given calorie level, if exercise improves average, but not maximum lifespan, just what exactly does this mean? The longest lived were never in any danger; they had excellent metabolisms, didn't need the boost from exercise. Or, because they had such excellent metabolism, they just naturally ran around the cage more than the other mice? What good would organized exercise do a hummingbird?
By their logic, a man who would have died at fifty, but extends his life to seventy through exercise, doesn't count; he didn't live to be 122. Maximum lifespan is fine, but doesn't ACTUAL lifespan count for anything?
On the article you actually posted about, it makes sense that protein might shorten life under some circumstances. Cancer cells need protein to grow too, just like regular cells. And that's what mice in these longevity experiments usually die from.
From what I can tell, though, sugar plus protein seems to be generally more growth (and proliferation?) promoting than fat and protein; sugar and protein tending more towards increasing synthesis, and fat and protein more towards reducing breakdown. They gotta do a longevity study with the Optimal diet already.