This flawed theory was largely spread by Ancel Keys, a diet researcher for whom military K-rations are named, and it was because of the lipid hypothesis that Americans were soon encouraged to substitute vegetable-based fats for animal fats, and to avoid red meat completely.
However, when Keys published his analysis that claimed to prove the link between dietary fats and coronary heart disease, he selectively analyzed information from only six countries to prove his correlation, rather than comparing all the data available at the time -- from 22 countries.
As a result of this "cherry-picked" data, government health organizations began bombarding the public with advice that has contributed to the diabetes and obesity epidemics going on today: eat a low-fat diet.
Of course, as Americans cut out nutritious animal fats from their diets, they were left hungry. So they began eating more processed grains, more vegetable oils, and more high-fructose corn syrup, all of which are nutritional disasters.
What about the Studies That DO Show a Link between Fat and Heart Disease?
Keys believed that dietary fat was causing heart disease in Americans back in the 1950s, and he soon got others to jump on the bandwagon.
Even the American Heart Association, which concluded in 1957 that "the evidence that dietary fat correlates with heart diseasedoes not stand up to critical examination," changed its position in 1960.
Why? Because Keys was on the committee issuing a new report that a low-fat diet was advised for people at risk of heart disease. Sadly, the theory continued to be accepted as nutritional wisdom, even though clinical trials found no connection.
There are, however, some studies that have found a link between fat and heart disease, and they are often used by saturated fat opponents to "prove" their case.
The problem lies in the fact that most of these studies make no effort to differentiate between saturated fat and trans fat <http://articles.mercola.com/sites/articles/archive/2001/07/21/trans-fat-par t-one.aspx> . I believe this is the missing link.
If researchers were to more carefully evaluate the risks of heart disease by measuring the levels of trans and saturated fat, I believe they would find a completely different story.
Trans fat is known to increase your LDL levels, or "bad" cholesterol, while lowering your levels of HDL, known as "good" cholesterol, which is the complete opposite of what you need in order to maintain good heart health. It can also cause major clogging of arteries, type 2 diabetes and other serious health problems.
On the other hand, your body needs some amount of saturated fat to stay healthy. It is virtually impossible to achieve a nutritionally adequate diet that has no saturated fat. What you don't need, however, are trans fats. Further, there are some people who do well with a low-saturated-fat diet -- the one-third who are carb nutritional types <http://articles.mercola.com/sites/articles/archive/2003/02/26/metabolic-typing-part-three.aspx>. Even then, however, some animal fats are necessary and healthy, and two-thirds of people actually require moderate- to high-saturated-fat diets to thrive.
Healthy Sources of Saturated Fats to Add to Your Diet
