The Low Fat Myth

The Low Fat Myth

For fifty years, hundreds of millions of people were given low fat, high carbohydrate (LFHC) dietary guidelines that were arguably not supported by scientific evidence of being healthy. How did we get it so wrong?

A Little Bit of History

To work out where we went wrong, we need to start as far back as the 1940’s with The  Framingham Heart Study, a long-term, ongoing  cardiovascular  cohort study  on residents of the town Framingham , Massachusetts. 

Framingham Heart Study 

Under the direction of the National Heart Institute (now known as the National Heart, Lung, and Blood Institute), the Framingham Heart Study was a long-term study, designed to identify the common contributing factors in CVD in a large group of participants who had not yet developed symptoms or suffered a heart attack or stroke.  Since its inception, over 1000 medical papers have been published with reference to the Framingham Heart Study but it is not without its flaws. One of the first two areas of interest of the researchers was to investigate how diet related to cholesterol levels and how diet related to the development of heart disease. This has led to one of the biggest criticisms and flaws of the FHS. 

High dietary saturated fat levels were blamed by the FHS as a leading cause of heart disease yet the FHS originally found that there was no relationship between a fat intake and a participant’s cholesterol level. When looking closely at the data it can also be found that lowered cholesterol levels correlates with an increase of CVD death in FHS participant over the age of 50. At the time of conducting the research these findings puzzled the researchers and were not included in their official report. 

Seven Countries Study   

We then turn to post-war Europe when researchers in the industry noticed a decrease in the incidence of heart disease. In 1956, a researcher by the name of Ancel Keys, started the world's first multi-country epidemiological study, which systematically examined the relationships between lifestyle, diet, coronary heart disease  and  stroke  in different populations from different regions of the world. 

Significantly, Keys studied the effect of dietary fat on health status. The European diet, he believed, was in vast contrast to the Americans, who were among the best-fed individuals in the world, consuming a diet high in animal fat. Keys assumed the post-war reduction in food supply (and therefore a lower fat diet) was a leading cause of the observed improved health status. 

From 1958 to 1964, Ancel Keys’ team correlated their data with heart disease outcomes in a series of regressions, plotting dietary fat intake against the heart disease deaths and assessing how closely heart disease deaths tracked with fat intake. First published in 1978, Keys’ work has since come under much scrutiny. It is a well-known fact that correlation doesn’t equal causation. It has also been proven that Keys selected countries when there were 21 for which data were available.

Analysis of the full dataset made the connections between fat intake and heart disease statistically less clear (Yerushalmy J, Hilleboe HE, 1957). In fact, the same data set has since been used to support the positive correlation between sugar and chronic disease, but at the time, was completely ignored. The influence of Keys on the world of nutrition has been unsurpassed. 

The plot thickens - “Big Food”, vested interest and corporate lies

In 1965 the food industry group, Sugar Research Foundation, paid three Harvard researchers $US6,500 (approximately $US50,000 today) to single out fat and cholesterol as the dietary causes of coronary heart disease and to ignore evidence that significantly pointed to sugar consumption as a leading cause. The "Hegsted equation", developed by one of the researchers David Hegsted, showed that cholesterol and saturated fats from sources such as eggs and meat in the diet raised harmful cholesterol levels, monounsaturated fats had little effect and polyunsaturated fats from sources such as nuts and seeds lowered cholesterol levels.  

Published in the New England Journal of Medicine in 1967, their literature review, ‘Dietary fats, carbohydrates and atherosclerotic vascular disease’, did not disclose the Sugar Research Foundation’s funding or role but did direct the course of our food guidelines and dietary recommendations for decades (McGandy RB et al, 1967). This paper is considered to have played the most significant role in distracting our attention away from the dangers of sugar and its role in chronic conditions including obesity and heart disease.  

Unfortunately funding from the food industry is not uncommon in scientific research. It is estimated that since 2008, one of the major players in the soft drink industry has spent close to 4 million dollars on research and upon analysis, their studies are five times more likely to find no link between sugary drinks and weight gain than studies whose authors reported no financial conflicts. 

As you are now well aware when it comes to our current dietary guidelines, the demonization of fat still exists. Fat will make you fat? Wrong. Every cell in our body contains cholesterol and fat and our neurotransmitters and hormones are made from the cholesterol found in animal fats. 

Your brain is over 60% fat, with more than 25% from cholesterol. Good quality fats provide nutrient density, satiety, hormonal control, brain health, heart health and an anti-inflammatory approach. You absolutely need fats to thrive.  

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Steph Lowe

Steph Lowe is a Sports Nutritionist (BSpExSc GDipHumNutr), triathlete, founder of The Natural Nutritionist, a hub for celebrating the importance of real food, and author of The Real Food Athlete.

With a passion for spreading a positive message about real food and the incredible effect it has on performance, Steph launched The Natural Nutritionist in 2011 and is on a mission to inspire others to make health a priority in their lives.