One billion people are considered too fat.

The worldwide rates of obesity have quadrupled in the developing world, jumping to around one billion since 1980.

The Overseas Development Institute, a think tank in the UK, says now one in three people are overweight, and it's urging governments to do more to influence diets and healthier living in order to prevent a huge increase in heart attacks, stroke and diabetes.

Overweight or obese is defined as a person having a body mass index greater than 25, and the global number of people meeting that definition has gone up from 23 to 34 percent between 1980 and 2008.

--Rob Archer