Lang, who, as well as working with government, is professor of food policy at City University, told delegates to the British Meat Processors' Association annual conference that the industry had to face up to the realities issues that were once marginal "stuff of the crazy greens" were now mainstream.
He said water was a bigger issue than climate change, and that production should be "drastically" reduced. Consumers needed to be encouraged to eat higher-quality meat, less frequently. "Everyone dances around the consumer, the consumer is god. But actually, the consumer is part of the problem and no-one says it."
He said the strategy had to change. "If we're selling meat consumption as an aspirational target, then we're committing public health suicide."
He said the UK had a dispro-portionate number of uplands unsuitable for crop production, but he said he was unsure whether it would be better to re-forest them, rather than use the area to produce meat. But he admitted that livestock production carried biodiversity benefits. He also said lowland areas should be used for crop production, not livestock and animals should be grass-fed only. "At the moment, 50% of grain production in the UK is going to feed animals. This is crazy."
When it came to the issue of meat and health, he said the tide of opinion was moving against the industry, and simply picking holes in various reports would change nothing.
Richard Cullen, consumer insight manager with the Agriculture & Horticulture Development Board, commenting on Lang's presentation, said: "It makes me think we need to have a counter-balance on the same committees that he's sitting on."