The Low Fat Doctrine: Part I
Craig F. Nelson, MS, DC
There are few cultural concepts as enduring as powerful or as consistent as our current notion of what constitutes a “healthy diet.” Ask 100 people to describe a healthy diet and chances are pretty good that most will give a similar response. Look at grocery store and menu items that are labeled as “heart healthy” and they will all have one thing in common. Conversely, Google the term “unhealthy diet” and look at the images that are returned. The cheeseburger would appear to be the deadliest food choice, followed closely by bacon in any of its forms.
The common denominator to all these concepts is fat, particularly animal fat. The imagery associated with this idea is powerful. We imagine that globules of fat on our plates will actually congeal inside your coronary arteries. Ultra-rich foods are described as a “heart attack on a plate.” Restaurants defiantly dare their customers to try their “triple-bypass burger.” This single message—I’ll call it the Low Fat Doctrine (LFD)—has been relentlessly promulgated for more than 50 years. And yet…
An analysis published this last March in the Annals of Internal Medicine (one of the top biomedical journals in the world) stated:
“Current evidence does not clearly support cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of total saturated fats.”
This rather understated conclusion is but the latest in what has been a relative flood of studies over the last few years that have undermined the LFD. The current state of the science finds that people following the standard low fat diet loose less weight, have poorer metabolic indicators of health, and suffer cardiovascular disease at a higher rate than alternate diets. What’s going on? How did the LFD come to be, and how and why did we manage to follow this false dietary doctrine for 50 years?
It turns out that the seminal event in the creation of the LFD occurred here in Minnesota. That was the research University of Minnesota physiologist Ancel Keys, PhD. Dr Keys was the lead investigator of what was known as the “Seven Countries Study.” As the name suggests this study compared the diets and the health status of seven different countries: The United States, Finland, Japan, Netherlands, Italy, Yugoslavia and Greece. On the basis of some initial findings from this study Dr. Keys declared in 1961:
“The only sure way to control blood cholesterol effectively is to reduce fat calories in the U.S. diet from 40% to 15% of total calories, and cut saturated fat from 17% to 4% of total calories.”
As the final data from this study were analyzed and reported they seemed to confirm this idea. At the same time other similar studies were underway such as the Framingham study which examined the habits and health of the citizens of Framingham, Massachusetts. Collectively these studies seemed to indicate that dietary fat (particularly saturated animal fat) and dietary cholesterol were associated with increased rates of heart disease and stroke. In addition to this science that seemed to support the LFD, it was supported by simple common sense. The primary lesion causing heart disease, deposits in the coronary arteries, were composed cholesterol crystals and other fat-like substances. It just made sense that consuming the substances that were ultimately deposited in the arteries would accelerate this process.
The second major milestone in the LFD was the 1977 report by the Senate Select Committee on Nutrition, led by Senator George McGovern. Relying primarily on the studies cited above the committee report recommended that Americans
- Increase carbohydrate consumption to 55% – 60% of total calories
- Reduce overall fat consumption
- Reduce saturated fat consumption and replace with mono-unsaturated and polyunsaturated vegetable oils
- Reduce cholesterol consumption
- Decrease consumption of red meat
- Decrease consumption of eggs and butter
- Substitute non-fat milk for whole milk
The anti-fat movement only intensified over the next 15 years. It reached its apotheosis in 1992 with the release of the US Department of Agriculture food pyramid shown below. It specifies that we consume 6 – 11 servings of “bread, cereal, rice and pasta” per day. And it relegates any type of fat to the same category as sugar—use sparingly.
By this time our incorporation of the LFD into our lives was complete. We had long ago begun substituting hydrogenated vegetable oil (margarine) for butter. The act of eating an egg was a form of nutritional daredevilry. The term “polyunsaturated” entered our collective consciousness. Commercial products were fashioned to meet the market demand created by the LDF. These products were labeled “Light” or “Lite” or “Heart Healthy.” And so by the end of the 20th Century the LFD was virtually unchallenged both in the scientific community and in the popular culture.
All of this had taken place without the benefit of…what’s it called? Oh yeah, science.
Next week, Part II: The Dissenters