Researching the history of sushi and its rising popularity in the United States, Corson found the popular belief that sushi is better for you than pizza is not always true.
In fact a sushi takeout box at an American supermarket could easily contain as many calories as two slices of pizza, and the sushi rolls served in restaurants are often worse.
"What we think of as sushi in the United States has become Americanised and that involves more fatty ingredients while the rice tends to be sweet," Corson said.
"There is a lot of sugar, carbohydrates and sodium in the rice and then there is the issue with fish, as when you eat fish anywhere, you have to be concerned about mercury."
Exposing the myth about sushi always being healthy was just one of the surprises that Corson came across as he researched his book The Zen of Fish.
As he traced the history of sushi in Japan, Corson found that it was not about eating raw fish with the word sushi simply referring to its essential ingredients rice seasoned with vinegar.
Sushi arrived in the United States via Los Angeles' Little Tokyo in the 1960s. It was introduced by a man named Noritoshi Kanai who worked for Mutual Trading Co. and had previously tried to introduce snake meat and chocolate covered ants to the United States as he looked for products to sell to Americans.
It has since gone from being an exotic and adventurous novelty to being offered everywhere from restaurants, supermarkets, to even sports arenas but bears only a passing resemblance to its original Japanese incarnation.