What goes around comes around, it is often said. T. Colin Campbell of the Physicians Committee for Responsible Medicine offers an interesting analogy along that line regarding American-Chinese convergence.

“From bird flu to SARS, Americans have worried themselves sick over diseases originating in Asia,” he notes in a recent Knight Ridder Newspapers piece. “But globalization has opened a door that swings both ways. Chinese authorities are now confronting a health crisis imported directly from the United States: an obesity epidemic sparked by the spread of high-fat, meat-heavy Western diets.”

Campbell, a nutritional biochemist, says the number of clinically obese Chinese has doubled since 1992. Hypertension and diabetes rates are soaring. So the government has swung into action. In the next few months, the Ministry of Health in Beijing is expected to issue the nation’s first nutrition regulations.

“As a diet and health researcher working with colleagues in China, I have observed the country’s emerging obesity epidemic. I believe this astonishing situation offers an important lesson to Americans. As we watch Western-style eating habits fuel a public health crisis in the developing world, we’re receiving a powerful reminder that solutions to our own obesity problem may lie in the wiser habits of the past,” writes Campbell.

Campbell has been director of the China Diet and Health Study during the past 25 years. He and fellow researchers have conducted what has been called “the most comprehensive large study ever undertaken of the relationship between diet and the risk of developing disease.”

When the project was begun in the 1980s, many feared that populous China could not feed itself. But while the nation has had a number of nutritional problems over the past 50 years, researchers have found that the plant-based diet consumed in many villages contained sufficient calories and was quite healthful. Their conclusion was that such dietary patterns, including plenty of carbohydrates but little or no animal protein, were the main explanation for the low rates of heart disease, obesity, cancer and diabetes in rural China.

Says Campbell: “… those healthful eating habits are disappearing as the nation’s economy grows and opens to the world. Fast-food restaurants such as KFC and McDonald’s are sprouting like weeds in China’s more affluent cities. Meat consumption has nearly doubled since the 1980s, according to a recent report by the Earth Policy Institute.”

Consider the irony of it all. Americans long have complained about China’s “exporting” of what they consider undesirable trends, ailments and products. Now China is likely to lash out at America for “exporting” its tendencies to create morbid obesity.

Diet and indulgences as points of derision are by no means new. Some time back, a Lawrence resident was touring the Tower of London. Being a bit historically challenged, he asked one of the colorfully attired Beefeater guards if it was true the British, at the Tower, had beheaded the chivalrous Sir Walter Raleigh, whom some Americans might consider a hero.

“Indeed we did,” responded the guard, “and if he came back we’d do it again!”

Why, asked the surprised American?

“Because he brought tobacco over here from the colonies to make us sick and also brought potatoes to make our women fat.”

So, really, there’s hardly anything new under the sun.