The average American’s diet is close to nutrient sufficient. It may be that with the addition of between one-half to one pound of vegetables a day, half of which are dark green leafy vegetables, which would add very few calories, it may become nutrient sufficient (compare The Square Meal Diet). Consider that:
“Among U.S. residents aged 65 years and older, 10.9 million, or 26.9%, had diabetes in 2010.“
-National Diabetes Fact Sheet 2011.
This means that 73.1% of our seniors do NOT have diabetes. All we need to do is boost 73% to near 100%, a mere incremental improvement. Why “near”? Why not 100%? Because of the bad genes in the population.
This 73% is quite good, considering that all bets are off by age 65, which I estimate is the maximum achievable human life span in a “state of nature” (5x the estimate age of puberty, which is typical of primates). This assumes that our bodies have never been through a serious selection process for longevity extension.
If we subtract all cases of degenerative diseases that first occur after age 65, then subject all other cases to a Pareto analysis (wherein roughly we subtract out the ~20% who have ~80% of the maladies), we would have a measure of the real health of the “average person” in this country. We do not have the statistics to do this, but if we did, we would find out that it is nowhere near as bad as scientists suppose. The average person is close enough to nutrient sufficiency to achieve it, and enjoy reasonably good health, without drastic changes to his diet and lifestyle.
The current maximum observed human life span of 122.5 years is entirely artificial, extended by application of advanced medical knowledge and well-disseminated know-how that would never have existed in a state of nature. The ancient Greeks had a good deal of such knowledge. For example, Aristotle’s Golden Mean precept, “Everything in moderation,” has become hackneyed. Yet, it is a formula for a longer and happier life than anyone could achieve in a state of (ignorant) nature.