Obesity is no longer just a rich country's problem. It's now taken hold in poor and emerging countries and is rapidly developing into an insurmountable health crisis. Type 2 diabetes, heart disease and some cancers are on the march in nation's ill equipped to treat sufferers or educate others about the dangers of getting too fat. It's predicted that by 2030 one billion people will be obese, so how will the world cope with its ever expanding waistline?