A study done by The Cranfield University and commission by the World Wildlife Fund (WWF) found that eating British-bred beef and lamb was better environmentally than eating meat substitutes imported from abroad, such as tofu and Quorn.
The reason: Production methods for meat substitutes are often energy intensive, highly processed, and often shipped great distances. The result is that meat substitutes often result in increased land under cultivation, raising the risk of deforestation.
The researchers concluded: ‘A switch from beef and milk to highly refined livestock product analogues such as tofu could actually increase the quantity of arable land needed to supply the UK.
As The Lonon Times noted "The findings undermine claims by vegetarians that giving up meat automatically results in lower emissions and that less land is needed to produce food."
Of course the best diet (for both the person and the planet) is both local, seasonal, and not very processed, and while it includes some meat (especially chicken), it is heavy on local cereals, tomatoes, potatoes, vegetables, fruits, beans, and grains.