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2013年5月27日星期一

8 Ridiculous Nutrition Myths



There is a lot of incompetence in the area of nutrition and health. Even health professionals seem to constantly contradict each other. Here are 8 ridiculous nutrition myths, thoroughly debunked.
1. A Calorie is a Calorie
It is a common myth that all that matters for weight loss is calories in, calories out.
Of course, calories matter. But the types of foods we eat are also important.
Here are 3 examples of how “a calorie is NOT a calorie.”
-Fructose vs. Glucose: Fructose is more likely to stimulate hunger, increase abdominal obesity and insulin resistance, compared to the same amount of calories from glucose.
-Protein: Eating protein can raise the metabolic rate and reduce hunger compared to fat and carbs.
-Medium vs. long-chain fatty acids: Fatty acids that are of medium length (such as from coconut oil) raise metabolism and reduce hunger compared to longer chain fatty acids.
Bottom Line: A calorie is not a calorie. Different foods affect our bodies, hunger and hormones in different ways.
2. Eating a Lot of Protein is Bad For You
Some people think that a high-protein diet will harm your kidneys and cause osteoporosis.
It is true that eating protein can make you excrete more calcium in the short term.
However, long-term studies show that protein intake is associated with improved bone health and a lower risk of fractures, not the other way around.
Studies don’t find any association with kidney disease either.
The two most important risk factors for kidney failure are diabetes and high blood pressure. Eating adequate protein helps with both, which should reduce your risk of kidney disease later in life.
Unless you have a medical condition, there’s no reason to be afraid of having more protein in your diet. It’s a good thing.
Bottom Line: Eating a high protein diet may be protective against bone fractures and reduce the two most important risk factors for kidney failure.
3. The Healthiest Diet is a Balanced Low-Fat Diet
The low-fat guidelines first came out in the year 1977, at almost the exact same time the obesity epidemic started.
This diet was never actually proven to work. It was merely based on observations.
The National Institute of Health decided to test this diet and funded the Women’s Health Initiative, which is the largest randomized controlled trial ever conducted on diet.
In this study, tens of thousands of women were placed on either a low-fat diet, or continued to eat the standard western diet like before.
The study went on for 7.5 years and the conclusions were very clear:
-The diet did NOT prevent weight gain. The low-fat group weighed only 0.4kg less than the control group after 7.5 years.
-The diet did NOT prevent heart disease either. There was no difference between groups after 7.5 years.
-The low-fat diet got tested. It didn’t work, period.
Bottom Line: There is no evidence that low-fat diets lead to better outcomes. The largest randomized controlled trial ever conucted on diet proves that the low-fat diet is completely ineffective.
4. Everyone Should be Cutting Back on Sodium
Sodium is a crucial electrolyte in the body and our cells need to keep it within a very tight range, or we’ll die.
For a long time, sodium has been thought to elevate blood pressure and therefore raise your risk of disease.
It is true that it can mildly elevate blood pressure in the short term.
However, studies do not support the idea that lowering sodium helps improve actual hard outcomes like heart attacks.
Randomized controlled trials on sodium restriction show that there is no effect on cardiovascular disease or death. They also show that sodium restriction may increase triglycerides and cholesterol levels.
Unless you have elevated blood pressure, there is no reason to avoid adding salt to your foods to make them more palatable.
Bottom Line: Sodium restriction has been thoroughly tested. None of these studies have found any evidence that it actually leads to better outcomes.
5. Saturated Fat Raises The Bad Cholesterol and Gives You Heart Disease
The myth that saturated fat raises cholesterol and causes heart disease is still alive today.
This ideas was based on some flawed observational studies conducted in the 60s and 70s.
Since then, many studies have re-examined this relationship and discovered that:
-There is literally no association between saturated fat consumption and cardiovascular disease.
-Saturated fat raises HDL (the good) cholesterol and changes the LDL from small, dense (bad) to Large LDL, which is benign.
-There is no reason to avoid natural foods that are rich in saturated fats. Meat, coconut oil and butter are perfectly healthy foods.
Bottom Line: Despite decades of anti-fat propaganda, saturated fat has never been proven to cause heart disease. New studies prove that there is literally no association.
6. Coffee is Bad For You


Coffee has gotten a bad reputation in the past.
It is true that caffeine, the active stimulant compound in coffee, can slightly raise blood pressure in the short term.
Despite these mild adverse effects, long term observational studies actually show that coffee lowers the risk of many diseases. Coffee can:
-Improve brain function.
-Help you burn more fat.
-Lower your risk of diabetes… in some studies as much as 67%.
-Lower your risk of Alzheimer’s and Parkinson’s.
-Protect your liver against cirrhosis and cancer.
Coffee is also loaded with antioxidants. It is actually the biggest source of antioxidants in the western diet and outranks both fruits and vegetables, combined.
Bottom Line: Despite coffee being able to mildly elevate blood pressure, observational studies show a strong and consistent reduction in many serious diseases like Alzheimer’s and type II diabetes.
7. Eggs Are Rich in Cholesterol And Can Give You Heart Disease
Eggs have been unfairly demonized because they contain large amounts of cholesterol.
However, dietary cholesterol doesn’t necessarily raise blood cholesterol and eggs have never been proven to cause harm.
If anything, eggs are among the most nutritious and healthiest foods you can eat.
They’re loaded with vitamins, minerals and antioxidants.
Studies show that egg consumption actually improves the blood lipid profile. They raise the HDL (good) cholesterol and change the LDL from small, dense to Large, which is benign.
Observational studies show no association between egg consumption and risk of heart disease.
Additionally, some studies show that eggs for breakfast can help you lose weight… at least compared to a breakfast of bagels.
Bottom Line: Eggs are one of the healthiest and most nutritious foods you can eat and there is no association between egg consumption and risk of cardiovascular disease.
8. Low-Carb Diets Are Ineffective or Dangerous
Low-carb diets have been considered dangerous because of their high amount of saturated fat.
For this reason, they have been thought to raise your risk of heart disease and other chronic illness.
However, since the year 2002, more than 20 randomized controlled trials have been conducted and compared low-carb against the standard of care, the low-fat diet.
In almost every one of these studies, low-carb diets:
-Cause significantly more weight loss than low-fat diets.
-Drastically lower triglycerides, an important risk factors for heart disease
-Raise HDL (the good) cholesterol.
-Improve blood sugar and insulin levels, especially in diabetics.
-Change the LDL cholesterol from small, dense (bad) to Large (benign) – which should lower the risk of heart disease.
-Lower blood pressure significantly.
Low-carb diets are also easier to follow and have an outstanding safety profile. There is no evidence of any adverse effects, despite the scare tactics.
They are certainly a much better choice than a low-fat, calorie restricted diet… which many mainstream organizations still push despite zero evidence of effectiveness.


(source:mailonline/Health)

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