Do you ever feel guilty when devouring a bacon sandwich? If yes, it's hardly surprising. Fatty foods have a pretty bad reputation, and we're encouraged to minimise our intake. But where does this attitude towards fat come from?
Much of what we think about fat seems to stem from guidelines to help combat coronary heart disease put in place over 30 years ago. Both the US and UK governments recommended that average daily fat intake should be reduced to 30% of total energy intake, with saturated fat limited to 10%.
Last week the validity of these recommendations was questioned, increasing debate amongst dieticians and leaving us a little confused about what we should be eating!
Researchers from the University of West Scotland considered the dietary trial data that was available before the 1983 UK recommendations were put in place. While they found a link between reduced fat intake and lower cholesterol levels, there was no link between dietary fat intake and mortality. The group went as far as concluding that these old dietary guidelines were based on insufficient evidence, and should never have been issued in the first place!
So does this mean we can start ignoring the recommendations and introduce more fat into our diet? Well, perhaps not based on these findings alone says Tom Sander, Professor of Nutrition at King's College London. He points out that heart disease rates have fallen in countries that have adopted the policy of reducing total fat.4 There is also now a significant body of research demonstrating the health benefits of reducing particular fats in the diet.
So that means fat is bad for us? Not everyone thinks so. In fact, some scientists like Professor Timothy Noakes think the opposite, believing fat to be the body's preferred fuel. He points out that since the guidelines were introduced, the incidence of obesity and diabetes has risen dramatically. Rather than fat, he believes that a diet high in carbohydrates, particularly refined carbohydrates and sugar, is to blame.
In her provocative book, The Big Fat Surprise, Nina Teicholz also argues that the vilification of fat does not stand up to close examination. Teicholz documents how the low-fat nutrition advice of the past sixty years has amounted to a vast uncontrolled experiment with, she believes, disastrous consequences for our health.
With expert opinion so divided, we may never be able to say for certain what the best diet is for long-term health. What everyone does seem to agree about, however, is that being physically active has enormous health and well-being benefits. Professor Dame Sue Bailey put it nicely in a report for the Academy of Medical Royal Collegespublished last week: " I believe that if physical activity was a drug it would be classed as a wonder drug, which is why I would encourage everyone to get up and be active."
Select Committee on Nutrition and Human Needs. Dietary goals for the United States. 1st edn. Washington: US Govt Print Off, 1977.
National Advisory Committee on Nutritional Education (NACNE). A discussion paper on proposals for nutritional guidelines for health education in Britain, 1983.
Harcombe Z et al. Evidence from randomised controlled trials did not support the introduction of dietary fat guidelines in 1977 and 1983: a systematic review and meta-analysis. Open Heart 2015; 2: e000196.
Available at: www.sciencemediacentre.org/expert-reaction-to-study-looking-at-historic-uk-and-us-dietary-advice-on-fats/ Accessed on 13.02.15.
Available at: realmealrevolution.com/the-facts Accessed on 13.02.15.
Available at: www.amazon.co.uk/The-Big-Fat-Surprise-Healthy/dp/1483014703 Accessed on 13.02.15.
Exercise - The miracle cure. Available at: http://www.aomrc.org.uk/general-news/exercise-the-miracle-cure.html Accessed on 13.02.15.