Who amongst us has never been under the assumption that eating fat makes us fat? In my 28-years of life, I haven't known a single person who didn't think this, or if they did, they never vocalized it near me. Sure some people ignore "fat is bad" and choose to "indulge," but I don't recall anyone telling me that fat is nutritious until the medical establishment came out with a tentative approval of "good fats" in the late 1990's. This fat demonization was something I never questioned. On the surface, it is a linear line of logic: you eat fat and then your body stores this same fat. The "good fat" approval in the 1990's was our first clue that there was something wrong with this conclusion. Today, let's look at a brief history of nutrition as it relates to medicine and politics. In future posts, I'll get into more detail on the science and evidence that underpins our current paradigm.
First, let's rewind to a time when our society didn't actually agree that fat was bad for us, which surprisingly wasn't a medical consensus until the early 1980's (and then backtracked with the omega-3 asterisk in the late 1990's).
1797: Scottish surgeon, John Rollo, detailed his success in treating diabetes in British Army officers stationed in the fruit-rich Caribbean with an "all meat" diet.
1863: An obese Brit, William Banting, published his "Letter on Corpulence Addressed to the Public," where he detailed a diet that helped him lose weight by giving up bread, milk, sugar, beer, and potatoes. His booklet was so popular in Britain that his name ("banting") became synonymous with dieting.
1889: Joseph von Mering and Oskar Minkowski observe that surgically removing the pancreas led to an increase in blood sugar, followed by a coma and eventual death.
1922: Two Canadian doctors, Frederick Banting and Charles Best, realize that homogenizing the pancreas and injecting the derived extract reversed diabetes mellitus. They win the 1923 Nobel Prize in Medicine for this discovery.
1925: French scholar, Jean Anthelme Brillat-Savarin, describes in "The Physiology of Taste" how fat prevents obesity by allowing for satiety. His book was so popular that it never went out of print and remains available today).
1952: President Eisenhower has a heart attack. The U.S. medical establishment is receiving many questions regarding the cause of heart disease and research on the topic becomes popular.
1953: Frederick Sanger sequences insulin. This is officially the "discovery" of insulin, since even though it had been isolated and used, we did not previously know it's chemical composition. Sanger receives a Nobel Prize in Chemistry for his work in 1958.
This brings us to the era where our modern nutritional guidelines were established. Two prominent doctors, John Yudkin and Ancel Keys, have a rather public, ongoing academic spar on the cause of cardiovascular disease. Yudkin strongly condemns sugar ("pure, white, and deadly") as the culprit, while Keys believes the cause is "artery clogging" saturated fat and cholesterol. Both sides have a lot of compelling data and this debate plays out in the scientific community until politics gets involved.
In 1967, Senators Bobby Kennedy and Joseph Clark toured the South to check on the progress of the Economic Opportunity Act of 1964, the landmark legislation of Kennedy's "War on Poverty." The senators saw thousands of American children who were going hungry to the point of starvation. CBS News covers the trip in a special program called "Hunger in America." The public attention to the issue causes increased political interest in the issue, particularly during the presidential election. The Senate debates the issue and forms the U.S. Senate Select Committee on Nutrition and Human Needs chaired by Senator George McGovern and, rather quick by Washington standards, becomes functional in 1968. (Historical context: Bobby Kennedy was assassinated on June 5, 1968 and Richard Nixon is elected president on November 5, 1968.)
In 1969, the committee works with the Nixon administration to organize the White House Conference on Food, Nutrition, and Health. The official recommendations from this bipartisan conference were to expand the food stamp program, improve child nutrition programs, improve other nutritional programs, and increase consumer protection information activities (e.g., nutrition labels). This is the impetus for the committee to create official nutrition recommendations.
For several years, the select committee held hearings in which it heard from academics, educators, nutritionists, doctors, and the public. What's most clear from the testimony, is that there is no consensus. The USDA even acknowledges on their official website that there was much controversy regarding the results. As I've alluded to before, the then-president of the National Academy of Sciences, Phil Handler, issued the following rebuke in his testimony: ''What right has the federal government to propose that the American people conduct a vast nutritional experiment, with themselves as subjects, on the strength of so very little evidence that it will do them any good?''
The motivations for the guidelines weren't malicious: they began with a society distressed at the societal failure of starving children in our own backyard. That being said, the guidelines were somewhat reckless. There was political pressure to produce something concrete from all these years of hearings, but all those hearings really produced was a lack of scientific consensus and no incontrovertible evidence for specific foods. Yet, the committee built a consensus for the guidelines by going with what seemed to have the most support.
The official U.S. nutritional guidelines were issued in 1977. Americans were instructed to increase their carbohydrate intake to 55 to 60 percent of calories and to limit dietary fat intake to no more than 30 percent of calories, particularly in regard to saturated fat. I'll get into further detail on the "evidence" behind this recommendation, but to summarize here, the reasoning for this looks similar to the "calorie is a calorie" logic.
"If a heart attack is caused by fat being trapped in arteries, we need to reduce the amount of fat we are ingesting so it doesn't build up in our arteries." Here again this reasoning disregards the fact that the human body metabolizes macronutrients in different ways for specific reasons. It's also a bit like blaming water for a clogged drain. "Pour less water down the drain and the pipe won't get clogged" doesn't sound logical to most people, yet this is exactly the same logic behind reducing fat intake. Is the plaque building up in our arteries a product of fat? Or is fat just getting stuck in something ELSE that is building up in our arteries?
There is other epidemiological evidence that has led to this consensus that fat causes heart disease; however, these studies conclusions are scientifically shaky. These same studies that are cited for why we should reduce fat intake, were strongly disagreed with when they were first published. I'll break a few of these key studies down in detail in a future post.
The point is, we didn't yet have the science to give nutritional recommendations based in hard facts. But a few powerful individuals decided IT SHOULD BE DONE ANYWAY. Since the late 1970s, the scientific community has developed a much better understanding of endocrinology (the study of hormones and the metabolism) and has much better evidence to establish revised nutritional recommendations. Unfortunately, these revised nutritional recommendations are contradictory to what is now conventional wisdom and it's difficult to reverse course 180 degrees. That's why this is something that may slowly build to become conventional wisdom, but for now will only reach the independent thinkers who seek it out.
I'll leave you with the following thought from Gary Taubes, keeping in mind the above timeline: "According to Katherine Flegal, an epidemiologist at the National Center for Health Statistics, the percentage of obese Americans stayed relatively constant through the 1960's and 1970's at 13 percent to 14 percent and then shot up by 8 percentage points in the 1980's. By the end of that decade, nearly one in four Americans was obese. That steep rise, which is consistent through all segments of American society and which continued unabated through the 1990's, is the singular feature of the epidemic. Any theory that tries to explain obesity in America has to account for that. Meanwhile, overweight children nearly tripled in number. And for the first time, physicians began diagnosing Type 2 diabetes in adolescents. Type 2 diabetes often accompanies obesity. It used to be called adult-onset diabetes and now, for the obvious reason, is not."
