More than half a billion men and women are clinically obese, a report backed by the World Health organisation (WHO), says. The figures, released recently, are nearly double those of 1980, leading doctors to say that a "tsunami of obesity" is unfurling across the world. What role should be played by governments and health-care systems in rich and developing countries to combat obesity? What measures are to be taken by the individual and community to overcome the problem? Send us your views.