Common Nutrition Misconceptions

Paul Harter Paul Harter
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According to the BMJ, the UK junk food industry spends 30 times more on advertising than the government spends on promoting healthy eating. The food industry funds a large part of the world’s scientific research on health and nutrition. The food and supplement industries are very big business. So too is the diet industry.

In so many cases, the latest dietary fad is based on studies that are flawed or, at best, inconclusive. While there is no single “one size fits all” healthy diet, the basic contours of what constitutes a healthy diet for most people has not changed at all for centuries – a balanced and varied diet, rich in whole foods (low in processed foods), including fresh fruits and vegetables, and good sources of protein and fat – not too much of any one thing, and nothing entirely off the menu. Most nutrition myths and misconceptions deviate in some way from this basic, time-honoured formula. Here, we examine three of the most common nutrition misconceptions...


Some Foods Are Bad For You

What They Say vs. The Truth

Too much sugar causes type II diabetes

No, it does not. Obesity and inactivity cause type II diabetes. Healthy people do not contract diabetes by eating sugar (though diabetics may want to restrict their sugar intake if their doctor so advises). Of course, sugar contains calories and eating too much sugar may lead to weight gain which may lead to obesity which increases the risk of type II diabetes.

Too much protein causes kidney disease

No, it does not (though people with kidney disease may want to restrict their protein intake if their doctor so advises).  Even at bodybuilding levels (2.5 to 3.0 grams/kg bodyweight per day), protein does not cause kidney disease.  At well in excess of that, it may cause inflammation in some people.

Gluten is bad for you

No, it is not (unless you are Coeliac).

Dietary cholesterol (eggs, full fat dairy, animal fat) is bad for you.

No, there is no conclusive link between the consumption of dietary cholesterol and adverse lipid profiles.  Of course, excessive consumption of fats may lead to weight gain and other adverse health outcomes.

High glycemic index carbohydrates (white bread, white rice, pasta) are bad for you

No, they are not. Carbohydrates are your body’s preferred fuel source. There is no reason for healthy people to restrict their consumption (though diabetics and other insulin resistant people should consult their doctor). Of course, excessive consumption of high GI carbohydrates may lead to weight gain and other adverse health outcomes.

Dairy is bad for you

No, it is not. Countless scientific studies show that eating dairy products promotes a wide range of favourable health outcomes.  Some people are lactose intolerant, but the large majority of us are not.

Saturated fat is bad for you

No, it is not. Saturated fat in moderation is fine. However, diets high in saturated fat that exclude other fats (particularly Omega 3 fatty acids) are not optimal. Of course, excessive consumption of fats may lead to weight gain and other adverse health outcomes.

Fruit juice is bad for you

No, it is not. It is true that fruit juice has less vitamins, minerals and fibre than whole fruit. It is less satiating than whole fruit. But no, it’s not bad for you. Of course, fruit juice contains sugar (fructose) and excessive consumption of fruit juice may lead to weight gain and other adverse health outcomes.

Trans fat is bad for you

For once, true.  The consumption of trans fats can significantly increase the risk of cardiovascular disease.


Vegetarianism is healthier than omnivory

The research does prove that, on average, vegetarians have better health outcomes than meat-eaters. It’s not surprising. If you take 100 random vegetarians and 100 random meat-eaters, the vegetarians tend to be more health seeking than the meat-eaters.

On average, the vegetarians exercise more, smoke less, drink less alcohol, meditate more and, not surprisingly, eat more fresh fruits and vegetables. So, although they do have lower overall mortality and morbidity, it may have little or nothing to do with their diet.  


Studies that have tried to reduce the impact of the confounding variables (for instance by recruiting vegetarian and omnivorous subjects from among shoppers in health food stores) show no meaningful difference in health outcomes between them. The study we have not yet seen is one that compares the health outcomes of vegetarians to the health outcomes of health seeking omnivores who eat plenty of fresh fruits and vegetables. Our best guess is that the omnivores might come out on top.



Some diets work better than others for weight loss

The diet industry is constantly trying to prove that some diets are more effective than others:  Atkins, Paleo, Stillman, South Beach, Beverly Hills, Weight Watchers, Gluten Free, Liquid, Keto, Mediterranean, Intermittent Fasting – the list goes on and on. 


The fact is only one diet works: the calorie deficit diet. What all diets have in common, regardless of name or made-up scientific basis, is that they only work by creating an average calorie deficit over time – consuming fewer calories than you burn.


That said, any one particular diet can be more effective than all the others for some people.  Once a calorie deficit is achieved, the diet that works best is the diet that you can adhere to best. Adherence is impacted by many factors, including how hungry you feel on a particular diet, how easy it is to control cravings, how satisfied you are by the food you do eat, how easy it is for you to reduce your consumption of certain foods, how satiating the foods you eat are for you, how much physical activity you are able to maintain or add. It’s highly individualised.



So, when you contemplate eating a healthy diet for yourself, perhaps think of what your grandparents put on the table. Chances are it was a balanced and varied diet, rich in whole foods (low in processed foods), including fresh fruits and vegetables, and good sources of protein and fat. And, if you want to lose weight, perhaps start by thinking which calories would be the easiest for you, personally, to cut out (regardless of what works best for Dr. Atkins, Oprah or anyone else).


  1. Marky Mark says:

    Very helpful article for filtering the fiction of popularly promoted diets from fact. Thanks for Keeping it Real!

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