IF fat is a feminist issue, then meat has become a moral one.

A recent surge in veganism driven less by animal rights than climate change consciousness and perceived health benefits has helped to polarise attitudes to red and processed meats, and given licence to people who want to police what other people consume.

It is in this context then that we have to understand some of the emotionally-driven reactions to a study this week which declared that, actually, the evidence for its harm to health was "weak" and there was little point in cutting down.

The scientists, publishing their findings in the Annals of Internal Medicine, reviewed the existing data and concluded that - for most people - eating less red and processed meat was associated with only a "very small reduction" in cancer risk.

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Even then, the basis for this conclusion was of "low certainty" - in other words, it is not even clear whether there is a real causal effect at all.

It seems unlikely that the study will sway eating habits one way or the other. But the findings fired up the Twittersphere as the meat promoters claimed vindication and pro-Atkins gurus said this was yet more proof that all our problems are down to sugar and carbs anyway.

Meanwhile, plant-based advocate Walter Willett, a US professor of epidemiology and nutrition, dubbed the research an "egregious abuse of evidence", and the World Cancer Research Fund said it would not alter its recommendations to limit red meat intake.

Professor Giles Yeo, a Cambridge University geneticist and obesity researcher, noted that the risk perception changed whether you looked at the findings on an individual or population level.

For example, the study suggests that if 1,000 people cut out three portions of red or processed meat every week for their lifetime, there would be seven fewer deaths from cancer, of any type.

Most people might take their chances and consider that the likelihood of them being one of those lucky seven are pretty small.

At a population level, however, that is 7000 fewer cases of cancer for every million people. As Prof Yeo pointed out, that's not exactly trivial.

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Furthermore, a major study in January said the only sustainable diet for the planet would be plant-based, and humanity would have to halve its red meat and sugar intake by 2050.

But does this give people a right to moralise about meat?

Maybe yes, but it the problem is it is counter-productive: brow-beating and lecturing will only entrench habits, not change them.

A more plant-based diet is almost certainly the direction of travel. But there are worse crimes against humanity than an occasional bacon roll.