Eat fat, don't eat fat?

Posted on May 23, 2016

The National Obesity Forum (NOF), a campaigning group, has caused something of a storm by declaring today that current official dietary guidelines could have 'disastrous health consequences'. Instead, NOF argues that fat, even saturated fat, is good for you: 'Eating a diet rich in full-fat dairy – such as cheese, milk and yoghurt – can actually lower the chance of obesity.'

The NOF report has received severe criticism. For example, Professor Susan Jebb of Oxford University, commented that 'dietary guidelines need to be based on comprehensive reviews of the totality of the evidence, assembled and reviewed according to agreed protocols to reduce the chances they may be affected by personal opinion or other biases. The new report from the National Obesity Forum fails this standard.'

The NOF report reflects a shift in attitudes to fat. Once regarded as Public Enemy No.1 by health experts, with decades of advice to eat less of it, recent evidence suggests that fat in general, and saturated fat, may well be benign. Even the BBC's Michael Mosley, never one to get too far out of line with orthodox opinion, has written: 'I still think most saturated fat, particularly if it comes from processed food, is unhealthy, but I have gone back to butter, Greek yoghurt and semi-skimmed milk, as well as cramming in lots more nuts, fish and vegetables.'

Nutrition is a devilish area of science to reach firm conclusions about. We can be confident that the absence of certain things from our diets - protein, vitamins, minerals, salt, fat - is bad for us. But whether the overconsumption of specific foods or components of food - other than outright gluttony - is bad for us is another matter. For example, to measure the effect of reducing fat, one would have to either decrease calorie consumption or increase the consumption of some other dietary component, most likely carbohydrate. So the cause of any result from such experiment could have more than one cause. Isolating the impact of fat, carbohydrate or calorie intake is difficult if not impossible.

Researchers and official (or self-proclaimed) 'experts' should therefore be rather more humble about what we can and cannot suggest to consumers as the basis of an ideal diet. Given that NOF has previously campaigned for the introduction of a 'fat tax', perhaps the lesson of today's report is that it would be wise for activists to cut out the scaremongering and be more circumspect about demands for legal intervention. Homespun wisdom like 'a little bit of everything does you good' seems about as far as dietary advice can honestly go. In that context, demands for taxes on sugar or fat, or demands that food manufacturers cut down salt content, are not justified by what we can know for sure about health.

What we need is an honest debate about the evidence we have about food without the politics - and then leave consumers to decide for themselves what they want and what their priorities are. Some health-obsessed salad munchers will want to build their entire diets around the latest official advice, whatever it might be. Others may well decide that the pleasure of a greasy fry-up or a burger is worth more to them than any possible risk of living a slightly shorter life. These are complex judgements that individuals should make. We don't need them made for us in Whitehall or Brussels.