How often do I find myself at a restaurant, debating between the prime rib and filet mignon, when my salivations are interrupted by a friend’s lament:
“Oh I want the steak but I’ll be good and get the low fat veggie pasta.”
Back in my SAD aka: Standard American Diet days, I’d eye my companion with a sort of envy, begrudging their self control (as I had none.) Now, however, I simply bite my tongue, eschew a soft sigh, and mumble something to the effect of, “Get the steak. It’s fine.”  The dinner table is no place for a debate on food politics, even though politics have defined its current manifestation.
Old habits die hard. Old dietary dogma based on myths? That may just be immortal.
There’s a very complicated and twisted history to the vilification of dietary fat. If you want the full story, consider reading Good Calories, Bad Calories: Fats, Carbs, and the Controversial Science of Diet and Health
But I shall attempt a brief summary.
Ancel Keys. I don’t think he and I would have gotten along so well…
It all started in the 1950s, when a scientist by the name of Ancel Keys theorized that high amounts of saturated fat (a type of fat naturally found in animal products) increased cholesterol and thereby promoted heart disease. In support of this idea, he published an extensive “Seven Countries Study” showing that countries with diets low in saturated fat experienced less heart disease. In 1961, Keys achieved celebrity status by gracing the cover of Time magazine to proclaim the evils of saturated fat. The American Heart Association, a private company funded by Procter & Gamble (manufacturers of Crisco, a notably soy-based fat) jumped on board. In 1977 the government joined the crusade, publishing its first Dietary Goals for the United States, which adovocated increased carb intake and decreased fat intake for heart health – the first government publication regarding diet risk factors.
The low fat diet for health mantra was born.
The problem? This colossal cultural shift was a vast assumption of medical advice based on inconclusive and skewed evidence. For starters, Keys’ “Seven Countries Study” was uncontrolled and correlational, looking at broad trends easily involving a myriad of factors, rather than cause and effect data. More importantly, while Keys gathered data for 21 countries, he cherry picked 7 which supported his theory. Countries with high dietary fat but low heart disease were omitted, such as France, Germany, Holland and Switzerland, as were those with low dietary fat but high levels of heart disease, like Chili. Contradictions were also dismissed, such as in Finland, where the Eastern side featured significantly more heart disease than the Western, albeit equivalent fat intakes. If you pick 7 different countries from Key’s data, the saturated fat/heart disease link evanesces.
Problems also brewed in Keys’ keystone (pun intended) country which supported his saturated fat/heart disease theory: the island of Crete (a basis for the Mediterranean diet). Keys visited the island during an anomalous time in their diet history, when they suffered dietary hardship from World War II. The study was also conducted during Lent, effectively minimizing meat and cheese consumption. The low fat dietary data Keys collected from this island of low heart disease was therefore not representative of the country’s normal, fattier, diet.
Actual controlled studies of fat in patient diets were overwhelmingly inconclusive, ultimately favoring no saturated fat/heart disease connection. As Taube notes, only 2 trials actually looked at a low fat diet’s effect on heart disease (as opposed to a polyunsaturated vs. saturated fat diet and heart disease). While one indicated a low-fat diet reduced heart disease rates, the other indicated it did not. As for the many other studies on polyunsaturated fats replacing saturated fats in diet in relation to heart disease, the results were even less supportive. Some showed polyunsaturated fat diets reduced heart disease, but increased death rates overall (kind of defying the purpose.) Others simply showed no correlation. In fact, a 2010 meta-analysis journal article reviewing 21 studies on reduced saturated fat and cardiovascular health reported that “there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD (coronary heart disease) or CVD (cardiovascular disease).”
And ironically, the government’s “Dietary Guidelines” published in 1977 were on point spirit wise, crediting the increase in degenerative diseases to diet. As its preface noted: “Major health problems are diet related. Most all of the health problems underlying the leading causes of death in the United States could be modified by improvements in diet.” Yet while the guidelines did advocate a lower sugar intake, they focused on decreasing fat intake and increasing carb intake. Why was fat demonized rather than sugar? Why did a “low-fat” diet strike the nation, rather than a “low-sugar” one?
As for the relationship between fats and cholesterol (Key’s original thesis), irony reigns,  since dietary cholesterol bears minimal effect on blood cholesterol. Cholesterol is a waxy lipid substance in the body responsible for a myriad of purposes, including building cell membranes, assimilating vitamins, and synthesizing sex hormones. It is found in dietary fat. However, the cholesterol you eat does not automatically pop up in your blood stream. (Unlike something else {cough} sugar {cough}.) Furthermore, cholesterol is divided into two main types: LDL and HDL. In excess, LDL, or “bad cholesterol,” can form plaque on artery walls, restricting blood flow and encouraging heart disease. HDL, or “good cholesterol,” removes excess LDL from the bloodstream. While dietary saturated fats do slightly raise LDL (or “bad”) cholesterol levels, they also simultaneously raise HDL (or “good”) cholesterol levels, which regulate LDL cholesterol. This renders them essentially insignificant in regards to total cholesterol levels. Furthermore, there are different types of LDL: dangerous dense, sticky ones, and puffy, billowy particles which are more benign. Fats tend to raise the better billowy version of LDL, while carbs raise the “bad version.” (Perhaps it is sugar, not fat, which increases heart disease?) In fact, the dietary fat which specifically raises bad cholesterol and lowers good cholesterol is trans fat, overwhelmingly generated in response to the demonization of saturated fat (oh hey low fat margarine!). Such irony.
Despite the utter lack of scientific evidence to reduce fat intake in the 1950s-70s, Americans were in a prime position to accept any heart disease theory offered, as officials proclaimed heart disease to be strikingly on the rise. In actuality, this “rise” was likely due to a myriad of factors, such as the final decline of deaths from infectious disease (thanks to modern medicine), which left older humans susceptible to degenerative diseases like heart disease and cancer. The year 1949 also saw the addition of “arteriosoclerotic heart disease” as a category on death certificates. After its inclusion, heart disease rates “rose” by 20-35% within the year (since it could now be cited.) Furthermore, the 1948 National Heart Act and creation of the National Heart Institute saw a substantial influx of government funding into heart disease awareness and prevention (beginning with an unprecedented $9 million for heart research). Eisenhower’s heart attack in 1955 sealed the deal for the new fearful heart ethos.
And perhaps most importantly, the American Heart Association, a private institution funded by the aforementioned Crisco sponsors, while initially skeptical of the sketchy science behind the attack on fat, ultimately chose to go with the anti-fat movement which was clearly so in vogue. In 1957, the AHA dismissed Keys’ theories as faulty, with insubstantial evidence. In 1960, despite no change in the evidence, the AHA adamantly proclaimed that “the best scientific evidence of the time” called for low fat intakes for heart health.
And so, advised to lower fat intake at all costs, despite a lack of legitimately supportive evidence, Americans eagerly turned to high-carb, low-fat diets featuring grains, sugar, and processed foods. Food manufacturers jumped on board by churning out polyunsaturated margins to replace butter, and “healthy” low-fat fake fats. (I cringe just typing this).
The damage was done.
Heart disease rates continued to rise. Oh, and we got the obesity epidemic and diabetes influx as a bonus!
So next time you choose that salad with low fat dressing instead of the steak, and decline the butter, you can know that politics have done their job at the dinner table. (If by doing their job, we mean potentially ruining your health while instigating a less satisfying eating experience to boot.) Go team! Now excuse me while I go munch on a Pork Chop.
