The U.S. doesn't even make the top ten. The secret to long life in Japan starts with their diets—one of the most important elements, says this salesman, is fish.

"I might be biased about fish, but I would say fish is largely responsible," says Yoshinobu Yoshihashi, Senior Vice President at Yoshizen Corporation.

Yoshihashi runs a shop at Tsukiji Fish Market, the largest wholesale fish market in the world. Even as diets change in Japan, fish and fresh vegetables are still a central part of the cuisine. The average Japanese person consumes more than double the amount of seafood than the Average American.

During a rapid auction, licensed bidders buy a majority of fish and vegetables for grocery stores and restaurants, in a matter of minutes.

"By eating vegetables, the body condition becomes very good, and also, you know, as a plus, it helps with meat and fish digestion and absorption," says Yoshiharu Kondo, President of Masayoshi Fruits & Vegetables, Inc.