The following summary is an extract from the excellent How to live a low-carbon life by Chris Goodall:

• Eat organic food. Organic food doesn't require fossil fuel-based fertilzer, saving the energy needed to produce the fertilizer and the greenhouse gases that result from its application to the field.
• Buy local food. Locally produced foodstuffs, bought directly from the producer or via a local shop, save transport. It will also probably save on packaging and manufacturing.
• Eat less meat and dairy. Farm animals, particularly dairy cows, produce methane. But organic dairy products probably don't save any carbon emissions and may actually increase methane production. Eating a vegan diet is a reliable way of reducing carbon, supplemented perhaps, by (non-vegan of course) local eggs, honey and other wonderful foods.
• Buying minimally packaged foods makes a difference both to the amount of energy used in packaging and in the methane resulting from packaging materials sent to landfill.
• Avoid processed food and cook the raw ingredients at home. The gas used per person for cooking in UK homes generates one third of the amount of carbon dioxide used in food manufacturing. Large industrial cooking processes may be efficient; but the manufactured foods need chilling and storing after cooking.
• Compost all organic materials, including food packaging.
• Buy simple foods, where possible, sold at ambient temperature rather than chilled. Avoid supermarkets for their obvious wastes of energy.
• Does being a vegetetarian help? By itself, probably not much. All things being equal, simply stopping eating meat will not reduce emissions very much, particularly if consumption of dairy products rises to compensate for eating less meat. Dairy cows produce twice as much methane as beef cattle. Becoming a vegan would definitely help.

Useful Links

Slow Food UK - aims to protect and preserve the traditional foods, defend biodiversity and promote food education.

Food Vision - Local Authority information portal to promote safe, sustainable and nutritious food and improve local community health and well-being.

Making Local Food Work - aim to 'reconnect people and land through local food  increasing access to fresh, healthy, local food with clear, traceable origins'.

Bringing the Food Economy Home - the benefits of localising food production and the need for deregulation of local trade

The Vegan Society - promoting ways of living free from animal products

The Vegetarian Society - information and recipes

Eating less meat could cut climate costs - New Scientist report 14/2/09

Rethinking UK Food Strategy - Chatham House - How can the UK's future food needs be met?

The Fife Diet - a local food experiment with the people of Fife signing up to spend a year eating local food

The Food Programme (BBC4)