Express. 'Stop eating meat and save the planet' says United Nations

Experts urged westerners to become "demi-tarians" by halving the amount of meat they eat.

A report for the UN Environment Programme said that pollution from fertilisers is threatening human health and the environment by causing phenomena such as toxic algal blooms.

It said that 80 per cent of the nitrogen and phosphorus used in fertilisers is consumed by livestock because it is used to grow the crops they eat.

The scientists, led by Professor Mark Sutton of the UK's Centre for Ecology & Hydrology, said eating smaller portions or having meat every other day would help slash pollution.

Europeans eat 35 per cent more protein than recommended by the World Health Organisation while Americans overeat it by 58 per cent - and most of it comes from meat.

Meanwhile regions such as Asia, and particularly, China, are increasingly eating meat as their economies develop.

Professor Mark Sutton, chairman of the International Nitrogen Initiative, said the West needs to set an example to help slow the world's growing reliance on meat.

He said: “To aim towards eating half of the amount of meat we are currently eating is a good starting point.

"We should aim to be demi-tarians - eating half the meat we have typically been eating."

We need to realise that over-eating is not healthy - not for the environment and not for ourselves.”

He added that this switch could reduce the risk of a repeat of the horsemeat scandal which has been triggered by long trans-continental supply chains.

The report was backed by Achim Steiner, United Nations Under-Secretary General and Executive Director, who said: “Whether we live in a part of the world with too much or too little nutrients, our daily decisions can make a difference.”