Members of China's People's Liberation Army march in Beijing in this 2005 photo. According to a new report, they've since gotten taller and wider. (Frederic J. Brown/AFP/Getty Images)

The People's Liberation Army, one of the largest armed forces in the world, has released a study on the physical welfare of its thousands of troops. The study, published in Chinese in the army's official newspaper and reported on by the Wall Street Journal's Josh Chin, warned that Chinese soldiers have gotten too tall and fat for some of their equipment. Rifle butts are too short for their longer arms and, more comically, soldiers assigned to tank divisions are sometimes too big for the tanks.

This is a problem with which the U.S. military is all too familiar: The Pentagon has been warning for years that rising obesity in the U.S. is reducing the military's ability to field and deploy appropriately fit servicemembers.

But there's a big difference here: American troops are too big because they're unhealthily overweight. Chinese troops are too big because nutrition is better, particularly in childhood, and they're more healthily robust. The troops, the survey found, have an average waistline five centimeters (about two inches) larger than the average 20 years ago. But average height has increased by two centimeters. In other words, this is a good problem.

We in the U.S. are so familiar with China's rise that we often forget how recently it was much weaker and poorer. Malnutrition was widespread, particularly in rural communities, which meant that lower-class Chinese who went into the military were more likely to be underfed and underweight. So, as the Chinese military grew and modernized (which it had to do in large part by designing its own military technology because of trade sanctions), it designed its equipment around troops as they were. Now they've outgrown the old gear.

But China has got this: The PLA report says it's measuring troops on 28 different metrics to figure out how to redesign military equipment for the now-larger force.

What's interesting about comparing the Chinese and American militaries' struggles with larger troops is that both problems are functions of development. As China becomes less poor, its troops are less undernourished. But as countries go from middle-income to high-income, as the U.S. is, their populations also tend to become more obese. The same economic growth that made Chinese soldiers healthier may also, if it continues, someday make them less healthy, as has happened in America. Maybe, in two or three generations, the PLA will have our problems.