The areas of nutrition and disease prevention are full of incompetence.
We have been wrongly advised to avoid saturated fat and cholesterol, despite no evidence of harm.
Here are the top 9 biggest lies, myths and misconceptions about dietary fat and cholesterol:
1. A Low-Fat, High-Carb Diet is The Optimal Human Diet
Back in 60s and 70s, many prominent scientists believed that saturated fat was the main cause of heart disease, by raising the "bad" cholesterol in the blood.
This idea was the cornerstone of the low-fat diet. Because of a few bad studies and misguided political decisions, this diet was recommended to all Americans in the year 1977 (1).
However, there wasn't a single study on this diet at the time. The American public became participants in the largest uncontrolled experiment in history.
This experiment didn't turn out very well and we are still suffering the consequences. This graph shows how the obesity epidemic started at almost the exact same time the low-fat guidelines came out (2):
The diabetes epidemic followed soon after. Of course, a graph like this doesn't prove anything. Correlation does not equal causation.
But it seems plausible that the low-fat recommendations made things worse because people started eating less of healthy foods like meat, butter and eggs, while eating more processed foods high in sugar and refined carbohydrates.
Even though there was little evidence at the time, the low-fat diet has actually been thoroughly studied in the past few years and decades.
It was put to the test in the biggest controlled trial in nutrition history, the Women's Health Initiative. In this study, 48,835 postmenopausal women were split into two groups. One group ate a low-fat diet (with the whole grains and all that) while the other group continued to eat "normally."
After a period of 7.5-8 years, the low-fat group weighed only 0.4 kg (1 lb) less than the control group and there was no difference in the rate of heart disease or cancer between groups (3, 4, 5, 6). Other huge studies also found no advantages for the low-fat diet (7, 8, 9).
But it doesn't end there, unfortunately... the low-fat diet recommended by most nutrition organizations is not only ineffective, it may even be downright harmful.
In multiple human studies, the low-fat diet has actually made some important risk factors worse, raising triglycerides, lowering HDL (the good) cholesterol and making the LDL particles smaller (10, 11, 12, 13). Despite miserable results in the studies, many nutritionists all over the world continue to recommend the low-fat diet that is hurting more people than it helps.
Bottom Line: There is no evidence that low-fat diets have any benefits. They do not cause weight loss in the long-term or reduce the risk of chronic diseases. Some studies show that they may even cause harm.
2. Cholesterol Rich Foods (Like Eggs) Are Bad For You
Nutrition professionals have had remarkable success with demonizing perfectly healthy foods. Probably the worst example of that is eggs, which are among the healthiest foods on the planet. Just think about it... the nutrients in an egg are enough to turn a single fertilized cell into an entire baby chicken.
Even so... because eggs contain large amounts of cholesterol, they were believed to cause heart disease. However, studies actually show that the cholesterol in the diet does NOT raise the bad cholesterol in the blood. Eggs raise HDL (the good) cholesterol and are not associated with an increased risk of heart disease (14, 15, 16, 17, 18).
What we're left with is an incredibly healthy food... loaded with vitamins, minerals and powerful nutrients that are important for the eyes and brain (19, 20, 21).
Keep in mind that almost all the nutrients are found in the yolk... the white is nothing but protein. Telling people to ditch the yolks may be just be the most ridiculous nutrition advice in history.
Bottom Line: Eggs were demonized because of the high amount of cholesterol, but new studies show that they don't raise cholesterol in the blood or contribute to heart disease. Eggs are among the most nutritious foods on the planet.
For the rest of the story: http://www.businessinsider.com/9-lies-about-fat-that-destroyed-the-worlds-health-2013-11