Water scarcity's effect on food production means radical steps will be needed to feed population expected to reach 9bn by 2050

Globesity - Fat's New Frontier The world is getting very fat, very fast and now the obesity epidemic has spread from rich countries to poor and developing countries it is likely 1 billion people will be obese by 2030. In our special examination of arguably the world's number one health issue, Globesity - Fat's New Frontier, Foreign Correspondent visits the new obesity hotspots - Mexico, Brazil, China and India - where hundreds of millions are gripped by weight issues and associated diseases.