The British Medical Publication, The Lancet, has released the study which suggests global obesity levels have doubled during the last thirty years.

In the developed world, Americans have the highest average Body Mass Index, BMI, Japan the lowest. People are also getting bigger in Latin America, parts of the West Asia and China reflecting increased affluence and changes in diet.

The Lancet study says that more than half a billion adults worldwide were obese as in 2008 which represents a doubling since 1980. Bad news considering heart disease, diabetes and cancers can all be linked with body weight.

However, there are signs that other health indicators are improving at least in high income economies.