I find the argument that cooked food provides the human eating it more energy very plausible, and am surprised that it is controversial. (Is it really?)<p>This article appeared some time ago on HN, suggesting that the advent of cooking, and the higher amount of energy we could derive from cooked foods, allowed us to evolve a reduced gastrointestinal system and our big powerful brains:<p><a href="http://news.bbc.co.uk/2/hi/8543906.stm" rel="nofollow">http://news.bbc.co.uk/2/hi/8543906.stm</a>