The US is reportedly challenging a strategy put forward by the World Health Organisation (WHO) aimed at tackling rising obesity levels.

The WHO wants to lower the recommended daily intake of sugar, salt and fat in a bid to lower obesity levels, which are reaching epidemic proportions.

However, according to a document leaked to the BBC, the US government has questioned the science behind the plan, criticising the strategy's focus on good and bad food. The US government has said acceptable levels of so-called bad ingredients, such as fat and salt, have not yet been established, reported BBC News Online.

Some scientists have accused the US government of sabotaging the strategy in order to protect big business, the BBC said.