What makes South Korean food so healthy?

The number of overweight and obese adults in developing countries has reached almost 1 billion according to a new report from British researchers.

The Overseas Development Institute says the figure has almost tripled since 1980. It says current alarming trends point to a huge increase in the number of people suffering with some cancers, diabetes, strokes and heart attacks as a result.

The BBC visited South Korea's Kwangjang Market in central Seoul to find out how Korean people try to stay healthy.