• Half the vegetables and 95 per cent of the fruit eaten in the UK comes from beyond our shores.
• Increasingly, it arrives by plane - and air travel gives off more CO2 than any other form of transport. Agriculture and food account for nearly 30 per cent of goods trucked around Britain's roads and, according to a Government report in 2005, the resulting road congestion, accidents and pollution cost the country £9bn a year.
• The term 'food miles' was coined in the 1990s by Dr Tim Lang, professor of food policy at London's City University.
• Although air-freighted produce accounts for less than one per cent of total UK food miles, it is responsible for around 11 per cent of the total CO2 emissions from UK food transport. That's because transport by plane generates 177 times more greenhouse gases than shipping does, for example.
• Food transport is responsible for 25 per cent of the kilometres clocked up by HGVs on our congested roads. ll these journeys around Britain mean that HGVs transporting food transport are responsible for a quarter of CO2 emissions.
• Each year an estimated 6.3 million tonnes of packaging comes into British homes, at a cost of £450 to the average family
• Up to one-sixth of the average household food budget goes on packaging and it makes up a third of our household waste. Processing and packaging also contribute to food's carbon footprint, as does keeping it chilled or frozen.

• Organic farming uses less energy because it relies much less heavily on fertilisers and chemicals used in intensive farming, the manufacture of which creates greenhouse gases.

• Meat is the most energy-intensive of all foods to produce, taking up larger amounts of water than any other food production - 2,400 litres of water to produce a 150g hamburger compared to 13 litres of water for a 70g tomato. Cows give off methane which contributes to global warming, too.

• A 2005 Defra report indicated that it can be more energy-efficient to import tomatoes from Spain by lorry than to grow them in a heated greenhouse in the UK. Lettuce grown out of season in the UK also compared unfavourably with Spanish salad when total carbon emissions were measured.

• Most farming relies heavily on artificial chemical fertilizers and pesticides. Around 350 pesticides are permitted, and it's estimated that 4.5billion litres of them are used annually. Organic farming strictly limits the use of artificial chemical fertilizers or pesticides. Antibiotics for animals are kept to an absolute minimum. Instead it emphasises farming methods such as crop rotation to keep the soil healthy and natural pest-control systems. Genetically modified crops are forbidden. Organic bodies also demand more space for animals and higher welfare standards. The Food Standards Agency (FSA) has been unwilling to endorse the nutritional or health benefits of organic food in the absence of strong scientific proof.
• In 2008, British consumers spent more than £2.1 billion on organic food.
• Only five years ago 70 per cent of the organic food bought in the UK was imported. Now imports account for only 30 per cent of the organic market.
• Intensive animal rearing accounts for 18 per cent of global greenhouse gas emissions,while transport of meat accounts for 13 per cent. Meat production accounts for nearly a fifth of the world's greenhouse gas emissions. That's more than all of the world's air and road transport combined.
• Livestock-rearing has also contributed to deforestation in the Amazon rainforest, as forests have been cleared to make way for cattle.More than two-thirds of now-deforested Amazon Basin land is taken up by cattle grazing.Much of the rest of the deforested Amazon Basin has been given over to growing animal feed, particularly soya.
• Carbon dioxide emissions from producing a single kilogram of beef are comparable to driving a car more than 250km (155 miles). Then there's the greenhouse gas - 23 times more powerful than carbon dioxide - that cows emit. In Britain, the methane given off by 10 million cows accounts for eight per cent of the country's greenhouse gases.
• Meat production of meat is a drain on water supplies too. It takes 17 times as much water to produce a kilogram of beef as it does to grow a kilogram of maize.
• British consumers are eating more meat than ever - 50 per cent more than in the 1960s.
• But, in the unlikely event of a mass overnight, world-wide conversion to vegetarianism, there would however be a devastating impact on economies and environments. The numerous breeds reared by humans ensures the maintenance of biodiversity, and animals can be an important part of a holistic farming system: they produce manure, are used for traction and transport in developing countries and they eat the parts of crops that humans can't.
• To keep us supplied with bargain birds, farmers pack up to 50,000 (and typically around 25,000)chicks into sheds, dimly lit to discourage movement and ensure they put on weight at an unnaturally fast rate. After reaching the required size twice as quickly as factory farmed chickens did just 30 years ago, the average intensively reared bird is ready for slaughter at 5-6 weeks old. By then there could be up to 19 birds per square metre.

• Free-range chickens must have access to the outdoors for at least half their life and are grown more slowly, for slaughter at eight weeks old (10-11 weeks if they are organic), which means they don't suffer the problems that afflict the fastest-grown chickens.
• Eighty-five per cent of UK eggs come stamped with the red 'Lion Quality' mark. The mark indicates that they're included in a food-safety scheme (all Lion Quality eggs are from hens vaccinated against salmonella)
• Sales of free-range eggs are soaring, and now account for 40 per cent of what we buy. While the UK has the largest number of free-range hens in Europe, demand for free-range eggs currently exceeds production. Yet more than half the eggs sold are laid by caged hens; four per cent are from barn hens.

Chicken

• The 'Red Tractor' symbol is part of a voluntary scheme. Birds with the symbol meet assurance standards, guaranteeing the health of the flocks and food safety. Red Tractor chickens have been reared to a minimum welfare standard. These are conditions for 'standard' chickens and already exceed the EU welfare rules being introduced in 2012.
• 'Extensive indoor' or 'barn-reared': these chickens mustn't be packed more than 15 to a square metre of living space (and not more than 25kg/sq m in combined weight); they shouldn't be slaughtered before they are 56 days old.
• 'Free-range': the maximum indoor stocking density is 13 birds per square metre (and not more than 27.5kg/sq m); in addition, each bird, for at least half its life, should have continuous daytime access to open-air runs with a maximum density of one bird per square metre.
• 'Traditional free-range': the maximum indoor stocking density is 12 birds per square metre (and not more than 25kg/sq m); continuous daytime access to open-air runs should be given from the age of six weeks, and these runs should allow at least 2sq m per chicken; poultry houses shouldn't contain more than 4,800 chickens. Slow-growing varieties of chicken should be used, with a minimum slaughter age of 81 days.
• 'Free-range - Total Freedom': in addition to the criteria for 'traditional free-range' chickens, these birds should have open-air runs of unlimited area.
• 'Organic' chickens are free-range and slower grown. They are slaughtered at 81 days, given organic feed and no routine antibiotics. They are kept in smaller flocks, with more space to move about inside and out.
• Freedom Food is the scheme for animals reared to the RSPCA's welfare standards. Chickens are more slowly grown and stocking densities are lower, though they are not necessarily free-range birds.

Eggs

• 'Farm fresh' is a meaningless description. The eggs could have been laid by chickens farmed in battery cages. Boxes must state whether eggs were laid by caged hens.
• 'Barn eggs' come from hens kept indoors in sheds, with no more than nine birds per square metre. Perches must be provided and other environmental conditions met. They can be Freedom Food approved.
• 'Free-range' egg production provides chickens with daytime access to runs covered with vegetation, with a maximum 2,500 birds per hectare.
• 'Organic' eggs are from chickens with more privileges than free-range and are produced according to EU laws on organic production. Growth promoters, artificial pesticides, fungicides, herbicides and commercial fertilisers cannot be used in the feed for organic production.
• The 'Lion Quality' mark on the shell of eggs is a guarantee that the eggs were produced to higher standards than required by UK or EU law. All Lion Quality-marked eggs have complete traceability, a 'Best Before' date on the shell and compulsory vaccination of the laying flock against salmonella.
• Freedom Food eggs meet the RSPCA's animal welfare standards. Battery hens do not meet the standard - only barn or free-range eggs qualify for this label.