The UN Food and Agriculture Organisation is taking seriously the farming of creepy-crawlies as nutritious food

Saving the planet one plateful at a time does not mean cutting back on meat, according to new research: the trick may be to switch our diet to insects and other creepy-crawlies.

The raising of livestock such as cows, pigs and sheep occupies two-thirds of the world's farmland and generates 20% of all the greenhouse gases driving global warming. As a result, the United Nations and senior figures want to reduce the amount of meat we eat and the search is on for alternatives.

A policy paper on the eating of insects is being formally considered by the UN Food and Agriculture Organisation. The FAO held a meeting on the theme in Thailand in 2008 and there are plans for a world congress in 2013.

Professor Arnold van Huis, an entomologist at Wageningen University in the Netherlands and the author of the UN paper, says eating insects has advantages.

"There is a meat crisis," he said. "The world population will grow from six billion now to nine billion by 2050 and we know people are consuming more meat. Twenty years ago the average was 20kg, it is now 50kg, and will be 80kg in 20 years. If we continue like this we will need another Earth."

Van Huis is an enthusiast for eating insects but given his role as a consultant to the FAO, he can't be dismissed as a crank. "Most of the world already eats insects," he points out. "It is only in the western world that we don't. Psychologically we have a problem with it. I don't know why, as we eat shrimps, which are very comparable."

The advantages of this diet include insects' high levels of protein, vitamin and mineral content. Van Huis's latest research, conducted with colleague Dennis Oonincx, shows that farming insects produces far less greenhouse gas than livestock. Breeding commonly eaten insects such as locusts, crickets and meal worms, emits 10 times less methane than livestock. The insects also produce 300 times less nitrous oxide, also a warming gas, and much less ammonia, a pollutant produced by pig and poultry farming.

Being cold-blooded, insects convert plant matter into protein extremely efficiently, Van Huis says. In addition, he argues, the health risks are lower. He acknowledges that in the west eating insects is a hard sell: "It is very important how you prepare them, you have to do it very nicely, to overcome the yuk factor."

More than 1,000 insects are known to be eaten by choice around the world, in 80% of nations. They are most popular in the tropics, where they grow to large sizes and are easy to harvest.

The FAO's field officer Patrick Durst, based in Bangkok, Thailand, ran the 2008 conference.

Durst helped set up an insect farming project FAO project in Laos which began in April. This involves transferring the skills of the 15,000 household locust farmers in Thailand across the border. "There were some proponents of a bigger dairy industry in Laos to improve a calcium deficiency," says Durst, whose favourite is fried wasp - "very crispy and a nice light snack". "But this is crazy when most Asians are lactose intolerant." Locusts and crickets are calcium-rich and 90% of people in Laos have eaten insects at some point, he says.Durst says the FAO's priority will be to boost the eating of insects where this is already accepted but has been in decline due to western cultural influence.

He also thinks such a boost can provide livelihoods and protect forests where many wild insects are collected. "I can see a step-by-step process to wider implementation."

First, insects could be used to feed farmed animals such as chicken and fish which eat them naturally. Then, they could be used as ingredients.

Van Huis adds: "We're looking at ways of grinding the meat into some sort of patty, which would be more recognisable to western palates."

One of the few suppliers of insects for human consumption in the UK is Paul Cook, whose business Osgrow is based in Bristol. However, no matter how they are marketed or presented, Cook is not convinced they will ever become more than a novelty. "They are in the fun element ... But I can't see it ever catching on in the UK in a big way."

• This article was amended on 2 August 2010. In the original, Professor Arnold van Huis was described as an entomologist at Wageningen University in Belgium. This has been corrected.