Yes. Someone actually went there. The Washington Post did an article talking about historic weight trends between the Japanese and Americans. The answer was kind of a big “duh.”

From the article.

“I am quite fat, actually,” said Michie Takagi, a 70-year-old grandmother and retired clothing store executive. She has a body mass index (BMI) of 19.9, which is at the thin end of normal. While the average American woman has gained about 25 pounds over the past 30 years, Takagi has gained 4.5 pounds, typical for her age cohort in Japan, according to U.S. and Japanese government figures.

Skinnier still are Japanese women younger than 60, who were thin by international standards three decades ago and who, taken as a group, have since been steadily losing weight.

The trend is most pronounced among women in their 20s. A quarter-century ago, they were twice as likely to be thin as overweight; now they are four times more likely to be thin. For U.S. women of all ages, obesity rates have about doubled since 1980, rising from 17 percent to 35 percent.

Before you start blaming this on “Genetics” or “healthy Japanese living,” the article goes on to say that Japanese men and children are getting fatter. It’s just the women that are shrinking away.

Now, from my own limited observations of Japan and from talks with Japanese women, I’ve come to the conclusion that Japanese women are starving. Oh yes. Starving. They don’t work out, as a whole, but instead get thin by eating next to nothing. It’s a constant game of thin brinkmanship. The result is a whole lot of twig thin women running around Japan. Something just as unhealthy as being overweight.

Via Japanprobe.