Philip K Dickhead writes "Bloomberg is reporting that the World Health Organization discovered a single, surprising characteristic that's emerged among swine flu victims who become severely ill: They are all fat. Infected people with a body mass index greater than 40 suffer respiratory complications that are harder to treat and can be fatal. The virus appears to be on a collision course with the obesity epidemic. WHO officials are gathering statistics to confirm and understand this development. 'It's very likely that if we went back retrospectively and looked at people who did poorly during seasonal flu, what would shake out is that obesity would be one of the risks.' Fat cells secrete chemicals that cause chronic, low-level inflammation that can hamper the body's immune response and narrow the airways, says Tim Armstrong, a doctor working in the WHO's chronic diseases department in Geneva."