Can we trust the food nannies?

Oops.
 
The dietary guidelines endorsed by the US and UK governments for the past three decades, which demonise fat as the number one nutritional villain, turn out to have been based on flimsy evidence.
 
A new study in the journal Open Heart has found that these guidelines, which advise restricting fat to no more than 30 percent of total energy intake and saturated fat to no more than 10 percent, should never have been issued. The guidelines were based on a non-randomised study of fewer than 2,500 middle-aged men, most of whom were already sick-hardly a sound basis for issuing dietary advice to millions of healthy men and women of all ages.
 
This is not the first time official diet advice has later been undermined by evidence. Saturated fat, it turns out, is not as bad for you as once was thought. Even the link between cholesterol and heart disease has been questioned.
 
Another public health myth that was recently debunked: the obesity explosion. Just one year ago, the National Obesity Forum in the UK was predicting rates of obesity were going to increase much more than expected and policymakers needed to prepare for an exponential rise.
 
As it turns out, rates of obesity have levelled off in the UK, especially among children. Here in Australia, childhood obesity plateaued a decade ago and in New South Wales may even be declining.
 
The same public health lobby that vilified fat 30 years ago has now moved on to sugar, with some scientists claiming that sugary foods are as 'addictive' as cocaine. This anti-sugar line is being used to justify policies like soft drink taxes and school candy bans.
 
But with its history of falling for dietary fads, like fat yesterday and sugar today, should we really trust these diet nannies to make food decisions for the rest of us? With their record of making doomsday predictions that don't come to pass, like the obesity 'bomb', should we trust them when they claim to have identified a crisis requiring urgent government action?
 
There is no one nutrient that is responsible for obesity. A person can grow to an unhealthy weight by eating too much fatty food or too much sugary food-the real problem is eating too much, period. This simple wisdom is something that most people already understand. The only problem with it, it seems, is that if everyone already understands it then there's no work left for nanny.

Helen Andrews is a Policy Analyst at the Centre for Independent Studies and will be speaking at the CIS event An Ounce of Prevention? on the 17 February 2015.