If you missed our post last week, hop back over there to read the first 6 big nutrition lies we've been told. Without further ado, #7.
7. Carbs Should Be Your Biggest Source of Calories The mainstream view is that everyone should eat a low-fat diet, with carbs being around 50-60% of total calories. This sort of diet contains a lot of grains and sugars, with very small amounts of fatty foods like meat and eggs. This type of diet may work well for some people, especially those who are naturally lean. But for those who are obese, have the metabolic syndrome or diabetes, this amount of carbohydrates is downright dangerous. This has actually been studied extensively. A low-fat, high-carb diet has been compared to a low-carb, high-fat diet in multiple randomized controlled trials.The results are consistently in favor of low-carb, high-fat diets (34, 35, 36).
Bottom Line: The low-fat, high-carb diet is a miserable failure and has been proven repeatedly to be vastly inferior to lower-carb, higher-fat diets.
8. High Omega-6 Seed and Vegetable Oils Are Good For You
Polyunsaturated fats are considered healthy because some studies show that they lower your risk of heart disease. But there are many types of polyunsaturated fats and they are not all the same. Most importantly, we have both Omega-3 fatty acids and Omega-6 fatty acids. Omega-3s are anti-inflammatory and lower your risk of many diseases related to inflammation (37). Humans actually need to get Omega-6s and Omega-3s in a certain ratio. If the ratio is too high in favor of Omega-6, it can cause problems (38). By far the biggest sources of Omega-6 in the modern diet are processed seed and vegetable oils like soybean, corn and sunflower oils. Throughout evolution, humans never had access to such an abundance of Omega-6 fats. It is unnatural for the human body. Research that specifically looks at Omega-6 fatty acids instead of polyunsaturated fats in general shows that they actually increase the risk of heart disease (39, 40). Eat your Omega-3s and consider supplementing with cod fish liver oil, but avoid the industrial seed and vegetable oils.
Bottom Line: Humans need to get Omega-6 and Omega-3 fats in a certain ratio. Eating excess Omega-6 from seed oils raises your risk of disease.
9. Low Carb Diets Are Dangerous
I personally believe low-carb diets to be a potential cure for many of the most common health problems in western nations. The low-fat diet peddled all around the world is fairly useless against many of these diseases. It simply does not work. However, low-carb diets (demonized by nutritionists and the media) have repeatedly been shown to lead to much better outcomes. Every randomized controlled trial on low-carb diets shows that they: Reduce body fat more than calorie-restricted low-fat diets, even though the low-carb dieters are allowed to eat as much as they want (41, 42). Lower blood pressure significantly (43, 44). Lower blood sugar and improve symptoms of diabetes much more than low-fat diets (45, 46, 47, 48). Increase HDL (the good) cholesterol much more (49, 50). Lower triglycerides much more than low-fat diets (51, 52, 53). Change the pattern of LDL (bad) cholesterol from small, dense (very bad) to Large LDL, which is benign (54, 55). Low carb diets are also easier to stick to, probably because they don’t require you to restrict calories and be hungry all the time. More people in the low-carb groups make it to the end of the studies (56, 57).Many of the health professionals that are supposed to have our best interest in mind have the audacity to claim that these diets are dangerous, then continue to peddle their failed low-fat dogma that is hurting more people than it helps.
Bottom Line: Low-carb diets are the healthiest, easiest and most effective way to lose weight and reverse metabolic disease. It is a scientific fact.
10. Sugar is Unhealthy Because it Contains “Empty” Calories
It is commonly believed that sugar is bad for you because it contains empty calories. It’s true, sugar has a lot of calories with no essential nutrients. But that is just the tip of the iceberg. Sugar, primarily because of its high fructose content, affects metabolism in a way that sets us up for rapid fat gain and metabolic disease. Fructose gets metabolized by the liver and turned into fat which is secreted into the blood as VLDL particles. This leads to elevated triglycerides and cholesterol (58, 59). It also causes resistance to the hormones insulin and leptin, which is a stepping stone towards obesity, metabolic syndrome and diabetes (60, 61).This is just to name a few. Sugar causes a relentless biochemical drive for humans to eat more and get fat. It is probably the single worst ingredient in the standard western diet.
Bottom Line: The harmful effects of sugar go way beyond empty calories. Sugar wreaks havoc on our metabolism and sets us up for weight gain and many serious diseases.
11. High Fat Foods Will Make You Fat
It seems kind of intuitive that eating fat would make you get fat. The stuff that is gathering under our skin and making us look soft and puffy is fat. So… eating fat should give our bodies even more of it. But it isn’t that simple. Despite fat having more calories per gram than carbohydrate or protein, high-fat diets do not make people fat.As with anything, this depends on the context. A diet that is high in fat AND high in carbs will make you fat, but it’s NOT because of the fat.In fact, diets that are high in fat (and low in carbs) cause much greater fat loss than diets that are low in fat (62, 63, 64).