Obesity, once considered an exclusively Western disorder, now poses a serious threat to the health of developing nations. According to scientists at the annual meeting of the American Association for the Advancement of Science in Boston, there is a global epidemic of overweight people.
Until recently, the main health challenges to developing countries were famine and infectious diseases like AIDS, malaria and tuberculosis. But obesity is now a looming specter too, wherever countries are undergoing a shift to urbanization, modern technology and food processing, and more leisure time.
University of Rhode Island anthropologist Marquisa LaVelle says the greatest increases in average body weight since the early 1950s have been among people in warmer climates. "Worldwide rates of obesity have increased to the point where many societies have both under-nutrition and over-nutrition," she observed. "Given the associations of obesity with chronic diseases - with diabetes, as high risk factors for heart disease and cancers of various sorts - this puts a burden on the developing world that they can ill afford."
In South Africa, Ms. LaVelle found urban Cape Town children taller, but significantly fatter than their ethnic counterparts in a rural area of the country, even in cases where social and economic status were similar. She also discovered that schoolchildren in Melbourne, Australia, are heavier for their height than their aboriginal desert counterparts.
University of Oxford researcher Stanley Ulijaszek says the weight problem is especially prevalent among rural South Pacific islanders, where up to two-thirds of men and three-quarters of women are obese. "If it is permeating the rural communities in these places, it is also permeating Amazonia, it is permeating rural communities across the world, so the epidemic is way beyond simply the industrial nations."
In the Cook Islands, the island of Rarotonga may be remote in terms of distance from most world capitals, but Mr. Ulijaszek says it looks like a New Zealand suburb and the effects of industrialization have reached it. As a result, Rarotonga adults have gained six centimeters in average height since 1952, but have gained more weight than is good for their new stature. "That means with globalization, we have a world food system," he explained. "America features strongly in the world food system, and the penetration of the world food system, the 'McDonalds-ization,' if you will, means that the dietary change can proceed faster in some of these remote places than was ever possible before."
Obesity is also on the rise among non-western immigrants to industrial countries. University of Michigan anthropologist Barry Bogin has studied Mayan children who have moved from the Central American nation Guatemala to the United States. They are an average of 10 centimeters taller and have longer legs than their Guatemalan counterparts, but Mr. Bogin says an alarming 42 percent are obese. "We found the children who report watching TV or playing computer games as their favorite leisure time activity face a high chance of overweight," he observed. "Many Mayan-American children are at risk for overweight and obesity and the serious health problems that overweight can bring to children and later in life."
The researchers dismiss the notion that specific genetic traits make some populations more prone to obesity than others. They say the weight gain has occurred too rapidly among too many newly-industrialized cultures to be accounted for by the gene pool. Nor can it be explained by a failure of personal discipline or psychological traits.
Marquisa LaVelle puts the blame on the modern way of living, with its dietary changes and decrease in physical activity. Although she says the impact differs among societies, she believes the solution rests less with dieting than with promoting physical activity. What is the alternative? "We are looking at a situation," she worries, "in which increased disease and decline in world health is inevitable.