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We once thought of obesity as the quintessential symbol of wealth and decadence. A problem of the rich West. Not so anymore: Fat is taking over the developing world as well. Around the globe, 1.6 billion people are overweight, 400 million of whom are obese. In fact—along with bird flu and HIV/AIDS—fat is the next global health threat of the 21st century, according to the World Health Organization. The problem? Trans fats, sugars, and a sedentary lifestyle form an often lethal cocktail that can result in diabetes, heart disease, and certain types of cancer.

It's true, in countries where being able to stuff your belly is still a privilege (Mauritania, for instance), chubby is usually considered sexy. But the standards the WHO uses to measure obesity around the world have nothing to do with the Western notion that thin equals beautiful. This is science, and its verdict is clear: 30 percent of the population is overweight in India, Brazil, Thailand and Russia. China leads the rankings of child obesity. And according to the BBC, if we keep chowing down, by 2015 there will be 700 million obese people worldwide. My advice? Invest in Chinese fat camps now, while shares are still cheap.