The author completely misses two boats:
1) Our brains as well as other genetic development really took off upon the invention of war, which is in effect high-speed evolution. If you match two tribes together in a battle, the smartest tribe usually wins. That is the reason our brains grew. Darwin knew this, yet modern liberal university professors are in denial because it doesn't fit in with the socialist utopian / narcissistic view of humans.
2) The author didn’t even read Atkin’s diet book, else would have learned that matching calorie intake to calorie consumption is an oversimplification. The author is too deep into the world is flat community that he can’t bring himself to realize he may have been wrong all these years.
I thought it was cooperation in the hunt and the eating of meat that contributed to the growth in brain size. Before you can fight, you need to eat. Social organization follows and you need socialization to wage war.