Top 5 Biggest Myths in Mainstream Nutrition


Biggest Myths in Mainstream Nutrition

I hate to admit it but there's a lot of nonsense in mainstream nutrition. Now, despite advancements in nutrition science there's some old myths that just don't seem to be going anywhere. In this article I'm looking at five of the big ones. The last one is just so ridiculous.

Number one,

egg yolks should be avoided because they are high in cholesterol, which drives heart disease. I remember when I was studying that we were taught people should cut back whole eggs because they're high in cholesterol. Or at least cut out the egg yolks. I'm not that old. It was thought that if you ate cholesterol, it would raise cholesterol in the blood and contribute to heart disease. Well that was wrong. The liver actually produces large amounts of cholesterol each day. When we eat more eggs, the liver just produces less cholesterol instead, so it basically evens out. It appears our response to whole egg consumption depends on the individual and the vast majority of people, it has no effect on total or LDL cholesterol. The exception is some who are genetically susceptible but even then it is debatable if the cholesterol increase actually influences heart disease risk. Aside from the protein, the yolks contain all the vitamins and other beneficial nutrients in the egg so if you're gonna eat the egg it's ridiculous to throw out the yolk.

Number two,

It is best to eat many small meals throughout the day to stoke the metabolic flame. It's often said that people should eat many small meals throughout the day to keep their metabolism high. Eating frequently may have benefits for some people like preventing excessive hunger, but it is incorrect that this effects the amount of calories we burn. Eating three meals of 800 calories has the exact same effect on total calories burned as eating six meals or 400 calories. There's literally no difference. Multiple studies have compared eating many smaller verse fewer larger meals and concluded that there's no significant effect on either metabolic rate or total amount of fat lost. It's quite clear for the average person that there's no advantages to eating more frequently. If anything eating fewer meals is beneficial in a society where we eat too many calories anyway.

Number three,

a high protein diet increases strain on the kidneys and can damage your bones. Although it's true that those with established kidney disease should cut back on their protein intake, this is absolutely not true for those who are otherwise healthy. Looking through the literature, there are no studies showing harmful effects of protein in the average person with healthy kidneys. In this thorough review, the authors conclude there's no significant evidence for a detrimental effect of high protein intakes on kidney function in healthy persons after centuries of a high protein Western diet. Even body builders who tend to eat very large amounts of protein, both from food and supplements, have healthy kidneys. There's also a theory that a high protein intake increases the acid load in your body, which then causes your body to take calcium from the bones to neutralize that acid. The longer term studies do not support this idea at all. Now a review from 2011 concluded there is no evidence that increased protein harms the bones. If anything, the evidence points to a higher  protein intake improving bone health, not the other way around. The same was found in a more recent review, with higher protein intake linked to better bone health. So that you can see that both these arguments against protein are just not evidence based.

Number four,

everyone should restrict salt to lower blood pressure and reduce heart attacks and strokes. The salt myth is still alive and kicking even though there has been no good evidence to support it at all. In a massive Cochrane review of 34 previous studies, salt restriction was shown to reduce blood pressure by only one to two points in healthy people, which is really unremarkable if your blood pressure is not high. Now in saying that restriction was found to reduce blood pressure by about three to five points in those with existing high blood pressure, which theoretically could be beneficial for cardiovascular health. I say theoretically because another Cochrane review found salt restriction has no effect on actually preventing heart attacks or strokes. Which is of course the actual end point we're trying to minimize when we tell people to limit their salt intake. So it may lower blood pressure ever so slightly, but it has no effect on cardiovascular death. For otherwise healthy people, sodium intake does not increase your blood pressure, and if it does it's very modest to the point where it makes no difference to your health. If you have existing high blood pressure on the other hand, it probably is beneficial to reduce your sodium intake just in case, but know that it won't have anywhere near the effect that losing excess belly fat would or reducing external stressors in your life.

 number five,

losing weight is all about will power and eating less and exercising more. Weight loss and gain is often assumed to be about will power and calories in versus calories out. That is so over simplified and untrue. The human body is a highly complex biological system with many hormones and brain centers that regulate when, what and how much we eat. Now it's well known that genetics, hormones and various external factors have a huge impact on body weight. Although it's still the individual's responsibility to do something about their weight, blaming obesity on some sort of moral failure, it's unhelpful and inaccurate. So if we look at calories in versus calories out, the calories in part of the equation is pretty straight forward. Only the food you eat can influence the amount of calories that go in. Of course the type of foods you eat can influence how many calories you consume. But it's really the calories out part of the equation that is much more complex than we've made it out to be. Genetic predisposition and hormones really greatly influence our metabolic rate, which is the energy or calories that you burn when at rest.

Now this has a much greater influence on calories out than increasing exercise or physical activity levels. So when addressing weight gain and obesity, our focus should really be on what foods and lifestyle activities can positively influence all these hormones. Not just how can we burn some extra calories on the treadmill.

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