Not long ago we were told to avoid fat, now we’re being told to avoid sugar as fat isn’t so bad. Do I avoid fat, sugar or both? The media has a huge impact on the public’s opinion of what food or macronutrients we should and shouldn't be eating. I looked further into the reason why this switch in public opinion may have occurred.

What informed the change in opinion?

In 1983 UK guidelines were introduced on dietary fat intake. We were advised to reduce this to 30% of total energy intake and reduce saturated fat consumption to 10% of total energy intake. These recommendations were made in the belief that dietary fat can increase our risk of coronary heart disease.

More recently a group of scientists sought out the research up to 1983. They looked into the studies these guidelines were based on - a study type called Randomised Controlled Trials (RCT’s) – the ‘cream of the crop’ in research design.

The results concluded that the initial guidelines in 1983 to reduce dietary fat intake should not have been introduced. Whether this means that changes to the health policy should be made is a more complex question.

So is this true? Can I eat more fat?

RCT’s are less accurate in dietary interventions as they are often poorly adhered to. There is every possibility that low fat diets had a positive impact on mortality, but was missed due to poor adherence to the diet suggested. Therefore (in short) the types of studies that have been recently scrutinised are not the most ideal to measure dietary outcomes.

There remains a whole body of evidence supporting a link between fat consumption and cardiovascular disease that needs to be considered first. There is certainly a strong argument that an overreliance in public health on saturated fat as the main dietary villain for cardiovascular disease has distracted from the risks posed by other nutrients such as carbohydrates or ‘sugars’.

Replacing one macronutrient (fat), for another (sugar), does not feel like a solution. It is very plausible that both can be harmful, or indeed a complexity of interactions between all macronutrients.

My verdict for now is therefore to stick to a healthy diet 80% of the time consisting of a rainbow of fruits and vegetables, a combination of wholegrain starches, low fat proteins dairy products and you can’t go far wrong. Remember the media can change your opinion in a split second but consider the quality of that evidence and where it has come from. Nutritionists and Dietitians use an evidenced based approach in their advice. They are able to sift through research and come to a reliable and realistic conclusion on what’s available.