McDonald's is a sponsor for the London Olympics — and a British doctors' group says that's sending the wrong message in a country with ballooning obesity. Big Macs, fries and milkshakes will be part of McDonald's exclusively branded menu at the Olympics and the fast-food giant will soon be opening its largest franchise in the world, a two-story cathedral-like restaurant that seats 1,500 customers, at London's Olympic Park. McDonald's will be the only restauranteur allowed to sell brand-name food at the games and there will also be a separate McDonald's within the athletes' village — in addition to three others at the Olympic Park....