By Antony Barnett

When you see a label claiming food is low fat or reduced fat or lean or skinny or light do you really know what it means? And when a nutrition label on the back of a product states the food only has 2.7g of fat in it how accurate do you expect that to be?

As part of our investigation into the food industry for Channel 4’s Dispatches, I wanted to find out. At a time when the nation is grappling with the obesity epidemic, consumers are being increasingly urged to choose their food carefully and this requires trust in how food manufacturers label their products.

Our fear of fat has spawned a lucrative sector in the food industry worth more than £5bn and my interest in this area was sparked by an investigation I did earlier this year examining the hidden sugar in food .We also probed the influential food lobby and exposed how the government’s chief nutritional adviser on sugar had paid advisory roles with Coca Cola and Mars. While it was this revelation that garnered most of the headlines I was equally shocked by the discovery that low fat food can contain a lot of sugar. In some cases for instance, a low fat yoghurt actually has more sugar in it than the full fat version.

Replacing fat with sugar

As the food industry take the fat out, they have to put something back in to keep their food tasty and appealing. In many cases, this is sugar. With a growing body of health experts blaming sugar as the primary cause of obesity and linking it to type 2 diabetes , this is a concern. For some consumers trying to look after their waistline and general health, opting for low fat could actually be counterproductive . Certainly many of the people we asked for our latest programme all thought low fat also meant low in sugar.

So what are the rules? Anything claiming to be low fat must have less than 3% fat. That’s it: food companies can put anything else in they want and as much of it as they want.

Marketing low fat food

Our investigation also seemed to provide evidence of what behavioural scientists called the health halo effect. When food is marketed in some way as being healthier then we eat more of it. One person we asked to only buy low fat food for a week actually ended up consuming the equivalent of 30 teaspoons of sugar in one day.

And it’s not just the “low fat” label that is causing public health experts and groups like the Consumers Association concern . Take for example the term “reduced fat”. This has to have 30 per cent less fat than a manufacturer’s standard product, but can still be high in fat. Or what about “lean” mince. One supermarket’s lean mince can actually have more fat in that the standard mince from another outlet. And as for the popular term “skinny” - well there doesn’t seem to be any rules about that. Starbuck’s skinny blueberry muffin has nearly 9 teaspoons of sugar in it, it’s classic blueberry muffin has 7.

Always check the label

The Food and Drink Federation told me that labels like low fat are just cues and consumers need to check the nutrition labelling on the back which tells them what is in the food. Putting aside how difficult it can be to understand some of this nutritional labelling, how accurate is it? The listing of ingredients on the packet to the nearest tenth of a gram certainly suggests a good degree of precision.

Dispatches decided to send one sample each of 50 different food products to a laboratory to compare the actual amount of fat content in the food to what the manufacturers claim on the label. The results genuinely shocked me.

More than half had more fat in them than the label claimed on the label. Many of us would accept there is likely to be some amount of variation but a fifth of our tested products had more than 20 per cent more fat in that the label claimed . Five had so much fat in that they breached trading standards guidance.

Extrapolating that across the industry would mean hundreds of thousands of products on our shelves could have significantly misleading labels . Traffic lights labels used to guide consumers could be wrong, and low fat foods might not actually be low fat. Indeed this was most striking in the case of Quorn “low fat” sausages. The first sample we sent came back with 41 per cent more fat than claimed meaning it breached labelling regulations . We sent off another 10 samples of these so-called low fat sausages and they all came back with so much fat in that they should not have called low fat. Marlow Foods, which makes Quorn, disputed our findings saying their own independent tests show the fat content is 2.7 per cent and compliant with low fat regulations.

Food labelling

To me, it’s clear that something is going wrong with our food labelling system. Our investigation found low fat products that were high in sugar, reduced fat products that were still high in fat and many products with a lot more fat in them than manufacturers claimed on the labels.

And remember Dispatches only tested products for their fat content. According to the scientist who carried out our tests - a man with 20 years of experience in testing food for trading standards and local authorities – our results are not atypical. He believed if we tested the ingredients of other food ranges we could well find similar levels of inaccuracies in the sugar and salt content.

Given the growing importance of our diets in terms of national public health and NHS budgets, it’s hard to think of an essential industry that is allowed to get away with so much.

Policing the food industry

The problem is that those charged with the day-to-day job of policing the food industry are trading standards . Budget cuts have left them overstretched and under-sourced while their officers are up against a powerful and well-funded food industry.

It seems that everyday there is another advert or health campaign trying to convince consumers to choose the right food. To do this the public needs to be able to trust what food companies tell us about their products . As our latest investigation has shown, at the moment, that seems a long way off.