The Food Pyramid And The Food Wars
Talking about nutrition and diet these days is stepping into an aggressive, entrenched war with unyielding positions on all sides. They say "virtue lies in the middle," but being in the middle is like being in a minefield, in no man's land, making you the target of everyone. By writing this text, I’m only trying to use a specific example to shed light on the need to scrutinize certain subjects before cementing an opinion, as there may be much more important details that we simply cannot see if we merely scratch the surface.
I believe that, just like me, you grew up with this image nearby:
I remember having a poster similar to this on the wall of my elementary school and studying it over the years as the basis for a healthy diet. You must have experienced the same thing.
The Food Pyramid has served as a guide to food choices worldwide since the 1980s. It was created by the United States Department of Agriculture (USDA) to steer Americans' nutritional choices in an attempt to combat the rise of heart diseases, which became the number one public concern after President Eisenhower suffered multiple heart attacks.
The indications the image provides are clear: the foundation of the diet should be grains, followed by vegetables and fruits. Consumption of fats and sweets should be as limited as possible, and there should also be a restriction on animal products.
The Food Pyramid is the graphical representation of the document Dietary Goals for the United States, the final report of the McGovern Committee. Written in 1977 by Nick Mottern, this document is the summary of the series of hearings Diet Related to Killer Diseases that took place in the U.S. Senate led by Senator McGovern during that year.
Since Mottern did not have a background in science, medicine, or nutrition, he chose Dr. Mark Hegsted as his scientific advisor. Dr. Hegsted was leading the American Heart Association, the largest association of cardiologists. He was an outspoken critic of meat consumption for ethical and environmental reasons and a strong advocate for a low-fat and animal-free diet as the best way to prevent cardiovascular diseases.
This low-fat dietary strategy, previously referred to as the "prudent diet for Americans," originated from the campaign led by Ancel Keys and Jeremiah Stamler against saturated fat. They believed that saturated fat was the cause of cardiovascular diseases and that eliminating it would lead to a reduction in heart-related deaths. This gave rise to the Diet-Heart Hypothesis.
At the core of this argument are observational studies conducted by both researchers in different populations around the world. The most well-known of these studies is the Seven Countries Study, in which they assessed the dietary patterns of populations in countries with low levels of these diseases, aiming to discover the best approach for health. The key territories in this study were Crete, Greece, and Southern Italy.
With excellent speaking skills and funding, they spread their conclusions to the four corners of the world: "These populations that don't suffer from heart diseases don't consume saturated fat or animal products! We've found the solution to our problems.", triggering 60 years of dietary recommendations.
At the time, these recommendations were widely criticized by doctors, lipidologists, and nutritionists, who pointed to the lack of sufficiently clear and robust scientific evidence to support the hypothesis that saturated fat from meat, by itself, could be associated with a higher cardiovascular risk. This criticism extended to the resulting recommendations.
I'll provide you with 3 particularities of the Seven Countries Study for you to draw your own conclusions:
Data collection took place in the 1950s, a time when Europe was recovering from World War II, with extremely high levels of poverty among the populations under study. The socio-economic environment made purchasing meat nearly impossible, which meant that their reduced meat consumption was not a free choice but an economic "obligation" (interestingly, when their economic power increased, they resumed meat consumption according to their traditions, without an observed increase in chronic diseases).
The third and final round of observational data collection occurred during a religious fasting period that prohibited the consumption of animal products, a fact not reported in the study's report. This led to the misconception that meat-free eating was the norm, when it was clearly the result of an extraordinary context.
The containers used to collect and send food for biochemical composition analysis in terms of macronutrients (carbohydrates, sugars, and fats) absorbed fat, reducing their fat content in the final analysis.
Any of these points should have dismantled Keys' theory. Nevertheless, despite the criticisms and pointed limitations (which continue to be highlighted), the message persisted and gained importance.
After the final document was drafted and approved by the members of the McGovern Committee, the USDA was established to enforce laws related to agriculture and food, particularly the guidelines included in Mottern's report.
To generate greater consensus and scientific support, the American Society of Nutrition was asked to review these recommendations and the science supporting them.
The conclusion was not as expected: there was only indirect evidence supporting the recommendations, not enough to justify their implementation.
It is important to note that high levels of saturated fat intake, particularly when combined with a lack of physical activity, can promote cardiac problems through processes such as atherosclerosis. However, foods such as meat can have a positive and significant impact on our health, even in greater daily amounts than the ones suggested by the pyramid.
Nonetheless, the process moved forward and became law.
This means that the creation of the Food Pyramid, the most influential nutritional information element in human history, was the result of a report written by a politician, advised by a prominent doctor with a bias due to personal opinions. It didn't undergo rigorous scientific review or gain high consensus within the scientific community. It was based on observational studies designed to prove a predetermined point and had serious technical flaws that would likely prevent its publication today.
The real point here is that we need to actively understand health norms, trends, or even advice. We should scrutinize how they came to light, their premises, and goals. Only then will we be able to discuss them – not just with our health assistants but also with our friends and relatives. By doing this, many potentially contentious discussions could become truly informative and mind-expanding, as they should always be.
04/07/2023
Posted originally - 23/06/2022 (https://www.cristinasales.pt/blog)