This is not my typical type of post or since I am really just getting started, what I intend my typical type of posts to be. 🙂 I promise more rainbows and sunshine! Read on for the a brief history of the low-fat diet and what that means for you.
I think it’s important to look at the history of nutrition science sometimes. There’s a lot of contradictory information out there and a lot of us have given up on what is and isn’t healthy because of it. There’s a reason the medical community and the American Heart Association have somewhat pivoted away from the low-fat, low saturated fat diet advice and started encouraging Americans to eat “healthy fats.” This is a fraction of one percent of the history but hopefully it will shed some light and provide greater perspective.
history of the low-fat diet
In the 1950’s, an epidemic of heart disease among relatively healthy middle-aged American men gained national attention. These men all had one thing in common-high cholesterol. John William Gofman , an American scientist, was convinced there was a clear link between cholesterol and Atherosclerosis, a cardiovascular disease in which plaque builds up inside arteries and the arteries become narrowed and hardened. This idea that there was a link between high saturated fat intake and blood cholesterol with heart disease became known as the “lipid hypothesis”.
In 1955, Ancel Keys, a prominent nutritional scientist at the University of Minnesota began conducting large-scale clinical studies in an attempt to prove the “lipid hypothesis” correct. In the infamous”Seven Countries Study”, Keys recorded the associations between diet and disease rates between populations and individuals within populations.
Keys did not choose countries at random, a violation of scientific norms; he selected only those likely to prove the lipid hypothesis correct. Data was published from the United States, Netherlands, Finland, Italy, Yugoslavia, Greece and Japan because this data supported the lipid hypothesis. It was found that while total fat intake was unimportant, saturated fat intake was a risk factor for coronary heart disease.
Critics have pointed out that Keys purposefully left out Switzerland, France, Sweden, Norway, Denmark and Germany because these populations consumed high quantities of animal fats and yet exhibited low rates of heart disease. The data from these countries simply did not match the lipid hypothesis so they were excluded. Conversely, data from countries such as Chile where fat consumption was low, but heart disease was high, was also left out.
It’s incredible that scientific community not only refused to denounce this study but celebrated the findings. In fact, in 1961 Ancel Keys landed a position on the nutrition committee for the American Heart Association. In that same year, the AHA began recommending that the American public reduce saturated fat and cholesterol intake from butter, fatty meat, egg yolk, and full-fat dairy, replacing them with low-fat polyunsaturated oils and margarine.2
This prompted physicians to encourage their patients to adopt a low-fat diet to prevent heart disease and sent food manufacturers scrambling to quickly formulate food products to be low in saturated fat and cholesterol.
the 1980’s: Low-fat Diet and jazzercise
By the late 1980’s all health-conscious Americans were following the strict low-fat diet endorsed by the American Heart Association. It was a time of low-fat margarine, steamed chicken breasts, and fat-free SnackWell’s cookies coupled with spandex leotards and Jazzercise.
My family was no exception… My mother replaced real, all-natural butter full of the newly demonized saturated fat with low-fat, I Can’t Believe It’s Not Butter, margarine. The marketing messages were clear. All-natural fats would lead to Heart Disease and chemical-laden, low-fat and fat-free substitutes created in a food science lab were something to be celebrated. Science had defied nature. We could have the same rich, buttery taste with little fat, fewer calories and zero guilt. This was healthy!
At the time, the average American didn’t know that there was very little evidence to support the low-fat diet… I would go one step further and argue that today most Americans are still trying to follow (in vain!) the low-fat diet without any knowledge that the data is flawed.
While more Americans are consuming less saturated-fat than ever, we are the unhealthiest population we have ever been. But in case you want to see the scientific data, check these charts out below. WOW!
I can only imagine what this chart would look like from 2009 to 2016. This is what I find so interesting… Butter and lard rich in saturated fats are at an all-time-low despite all of the talk that Americans are consuming too much saturated fat while polyunsaturated oils are at an all time high.
What is even more telling is the chart below. Plant-based polyunsaturated oils (soybean, corn, and sunflower), the oils promoted by the American Heart Association, is at an all- time-high and so is obesity, heart disease and diabetes.
I would love to provide a chart of the Long-Term Incidence of Heart Disease but after an arduous search, I don’t think it exists. There are a lot of charts that span 40 years showing the decline of heart disease related deaths but let’s be honest, that’s not the same thing. Of course heart disease related deaths are the lowest they have ever been; it’s directly proportional to the rise in incredible, life-saving, medical interventions.
But I can tell you this, according to the CDC, heart disease is the leading cause of death for both men and women with about 610,000 people dying of heart disease in the United States every year–that’s 1 in every 4 deaths.
Correlation Does NOT Equal Causation
Now I know that correlation does NOT equal causation. But, maybe it’s not as simple as the more fat we eat, the more we weigh and the unhealthier we are. Take a look at the U.S. Sugar consumption. Scroll up and compare the other charts. If we transposed all the data onto one chart… I believe the trendline would be quite telling.
We also have to consider the American philosphy of nutrition. Once we were told fat is “bad”, we avoided fat at all costs but gorged on foods high in sugar and carbohydrates, eating endless boxes of SnackWell fat-free cookies without regard to the volume of calories consumed.
The way I see it, there are a number of contributing factors to heart disease. And unfortunately, the science just doesn’t prove that by simply reducing the dietary intake of saturated fat, will reduce risk of heart disease. We have had half a century to prove Ansel Keys right by eating a low-saturated fat diet; Americans eat lower saturated fat as evidenced in the chart above and yet we are the unhealthiest population we have ever been.
Always with you, Sarah
Comment Below! Tell me about your experiences with the low-fat diet. Challenges? Successes? I’d love to hear from you.