[dpark]

> our ancestors did not have a long life expectancy

Historical life expectancy was skewed because of high childhood mortality. If you look at modern hunter-gatherers, life expectancy is still in the 30s, but life expectancy at age 15 is 54. This is still short by modern standards but everyone isn't/wasn't dying in their 30s.

edit: Forgot link to paper: http://www.unm.edu/~hkaplan/KaplanHillLancasterHurtado_2000_...

[rhinoceraptor]

Also, our life expectancy is increased even further due to modern medicine. But that isn't a validation of modern diet and lifestyle, we're just really good at stuff like fixing broken arms and treating infections.