Swing and a miss. Strike 1.
Humans have been eating meat closer to 2.5 million years. There is strong evidence that humans mental evolution happened faster once their diet improved to include more animal products.
There is emerging evidence that the surge in attention deficit disorders in the late 1980s and 1990s along with increases in other chemical imbalance issues in growing children mirrors the trend toward low fat diets.
As much as people hate to admit it, our bodies have built dependencies on a steady supply of small amounts of animal protein and fat. While not a cure, simply drinking whole milk daily has been found to ease ADD symptoms in some young children as well as drugs without the side effects. The older the kid the less effective whole milk is because the damage has already been done.
Adult vegans or vegetarians who have already completed their growth curves are a different story as their bodies needs are different. To deny that difference is folly.
The problem with most peoples diets is not the fat or meat content, but the quantity. The roots of the obesity epidemic is another discussion for another time.
