People will have to be rationed to four modest portions of meat and one litre of milk a week if the world is to avoid run-away climate change, a major new report warns.
The report, by the Food Climate Research Network, based at the University of Surrey, also says total food consumption should be reduced, especially "low nutritional value" treats such as alcohol, sweets and chocolates.
It urges people to return to habits their mothers or grandmothers would have been familiar with: buying locally in-season products, cooking in bulk and in pots with lids or pressure cookers, avoiding waste and walking to the shops - alongside more modern tips such as using the microwave and internet shopping.
The report goes much further than any previous advice after mounting concern about the impact of the livestock industry on greenhouse gases and rising food prices. It follows a four-year study of the impact of food on climate change and is thought to be the most thorough study of its kind.