Japanese population getting smaller in more ways than one

I didn't notice this story getting any attention in the media a couple of weeks ago after it appeared in Science - which is a bit surprising.  Because I, for one, did not know that it was well acknowledged that the Japanese have started getting shorter!:

Japan's obsession with slender women may harm unborn children and create long-term health problems for the Japanese population. Already, a high proportion of Japanese women is starting pregnancy underweight, and many scientists have criticized the country's official guidelines for weight gain during pregnancy as too strict. Now, a survey shows many pregnant women strive to keep their weight gain below even those targets. This combination of factors has led to an unusually high percentage of low-weight births, which is likely the reason that the height of the average Japanese adult has declined every year for those born after 1980....

The shortening of the Japanese is subtle, but unmistakable. An international study published in 2016 found that since the late 19th century, the average Japanese adult male height rose 14.5 centimeters, peaking at 171.5 centimeters for those born in 1978 and 1979. But by the 1996 birth cohort, it had dropped to 170.8 centimeters. Over the same period, average female height jumped 16 centimeters, topped out at 158.5 centimeters, then dropped by 0.2 centimeters. Some other countries have also experienced height declines, which the study variously linked to economic privation, an influx of shorter immigrants, or—in the United States—poor diet quality, which can impair growth both in the fetus and in newborn babies.

In Japan, experts say the evidence for a link with lower birth weights is strong. As the country recovered from World War II, the percentage of low–birth weight babies—those weighing 2.5 kilograms or less at delivery—declined from 7.3% in 1951 to 5.5% in 1978–79. As babies grew heavier, however, doctors worried about preeclampsia, a complication that can put the lives of both mother and baby at risk. In the late 1970s, some Japanese obstetricians suggested a low-calorie diet could lower that risk, a view incorporated into 1981 guidelines from the Japan Society of Obstetrics and Gynecology. "Previously, mothers-to-be were told to ‘eat for two’; now, the ideal is to ‘give birth small but raise a big baby,’" says Hideoki Fukuoka, an obstetrician at Waseda University in Tokyo.