For every four adults in the world who are malnourished five more are overweight, 30 percent of them clinically obese, according to the World Health Organization. The scourge of obesity, bringing in its train a host of health and economic problems that could one day cripple economies, is more prevalent in some countries than others, but still constitutes a global epidemic, says WHO. A billion people out of the world's six billion population are now considered overweight, compared with 800 million who do not have enough to eat. Some 2,000 health experts gather in Boston, Massachusetts on Friday for...