In an effort to improve residents health, King County in the us state of Washington banned the use of artificial trans fats for cooking at restaurants. It also asked nutritional information of foods to be mentioned in restaurant menus.

The ban comes into effect in May 2008. Restaurants have until February 2009 to find an alternative. Trans fats are produced by hydrogenation of vegetable oil and cause obesity and chronic diseases like diabetes. There has been a 37 per cent increase in obesity in the county since 1987.

New York city was the first to impose a trans-fat ban in 2006. The ban came into effect in July this year. The us state of Massachusetts and cities like Philadelphia, Miami, Chicago and Cambridge are also considering a similar ban.