This makes Freakonomics sound like Nobel material. Completely vacuous. He uses the comparison that most men are looking to date skinny women, but that many men are "afraid" to act on their attraction to overweight women. Yet... nearly 40% of women are considered obese. About half are married or otherwise attached. Who is to say that the population of online daters strongly correlates with these terrified men?
That's ironic considering he was a guest on an earlier Freakonomics episode: http://freakonomics.com/podcast/big-penis-things-ask-google/