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There's A Simple Reason Why People Ignore Nutritionists' Advice

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This week, the New York Times published an intriguing infographic that suggested a gap between what the public thinks of as healthy, and what nutritionists believe to be healthy.

The biggest chasms between public and professional opinion? Nutritionists generally poo-pooed the public's beloved granola bars, frozen yogurt and coconut oil. And you are apparently not as enamoured of our nutritional darlings, quinoa and tofu.

Since it is the role of nutrition professionals to guide the public in making healthier choices, how does this even happen? First, you have to start with the problems inherent in translating nutritional science into nutritional advice.

The Problem with Science

As a practicing dietitian, I know firsthand the challenge of crunching my theoretical knowledge of nutrition and health with current published research to create a secret sauce of nutritional advice, "perfect" for the utterly unique individual that is you.

More often than not, there is a chasm between what is known about the human body, what is hinted at in the scientific literature and the complex needs of a real human being. How I wish that there was a study that pertained to every single individual I counsel. But doing a study on the effect of probiotics AND kale for someone with irritable bowel syndrome AND depression AND high blood pressure doesn't appear to be a popular academic move. And so, my nutrition advice navigates minefields of uncertainty and assumptions on the daily.

In interpreting the nutritional science for real life, you have to accept that the field is inherently flawed. Dr David Katz wrote an excellent piece on this very conundrum.

The Coles Notes version is that a well-designed scientific study is hard to come by. Most studies are pretty reductionist in nature, testing easy-to-isolate nutrients like omega 3 supplements or saturated fat intake. However, research like this has very little real-world application. Because unless all you eat is lard, the overall impact of saturated fat within a varied diet is kind of hard to pin down.

The best kind of nutrition science is almost impossible to do because it flies in the face of both human nature and research budgets. The most helpful, real-world-applicable studies are feeding studies. Ideally, you could take 10,000 people from all over the world, put them on a deserted island so that they couldn't eat anything other than your study diet for 20 years and observe what happens to them.

This is not going to happen -- when feeding studies are done, it's usually a handful of people bunking in a university dorm for seven days. You can't really extrapolate that to long term consequences... and chronic disease is very much about playing the long game.

The practical compromise is reliance on relatively murky info. Like asking people to remember how often they ate broccoli over the last year and cross-referencing that with how many of them get cancer. Or treating some cancer cells -- or rats with cancer -- with an isolated broccoli compound and hoping we can unearth a mechanism for why it might work.

Individual beliefs about food and nutrition are very personal and most people don't like hearing that their beliefs may not be correct.

You say po-tay-toe... I say po-tah-toe

Of course, the very nature of research leaves it susceptible to interpretation biases. The scientific method demands that we form a question, test it and publish it for public scrutiny. Other researchers (hopefully) test and test and test until the science either backs it up or tears the theory down. This takes a long time. And yes, individual studies are often conflicting. But our hunger for health information drives the media to relay the results of scientific studies like they're sports scores. So today, high fructose corn syrup will kill you... and tomorrow, it won't.

But science still counts. People may think coconut oil is a superfood because the Internet tells them so; however, dietitians are going to point at the relatively small stack of literature on the benefits of coconut oil and say "not so fast." Doesn't mean it's bad for you... but it's not magic, either.

Of course, the fact that a human -- with all of their own unique experiences, education and biases -- is providing nutrition information is also a bit of a problem. For example, my bias is towards plant-centred diets, based on my interpretation of the research I have seen, my knowledge of human health, my ethics and my experiences seeing the results of this advice. But I certainly haven't seen every single study ever in existence on the subject.

I doubt very few people -- save for those researching the topic -- have. No professional can provide perfectly informed, unbiased information. But, at the very least, nutrition professionals are well equipped to do the best possible job. If only we were the only ones out there giving advice.

Quieting the nutritional noise

The practice of nutrition is a total minefield. Individual beliefs about food and nutrition are very personal and most people don't like hearing that their beliefs may not be correct. If you look at the full results of the NYT survey, the inconsistencies are glaring.

Given the very obvious state of overweight, obesity and chronic disease in America, it is surprising that only 20 per cent rated their health as fair or poor, and 81 per cent responded that they have enough information to help them decide whether a food is healthy or not. However, 78 per cent of respondents thought orange juice was healthy -- and only 10 per cent thought cola was. These two beverages have almost the same sugar content (and no, your body can't tell the difference between the two).

Compounding our total irrationality about our eating habits is the fact that since we all eat... it apparently makes us all experts. Except that it doesn't.


In addition to the regulated professionals actually trained in doling out nutrition advice, a whole host of other voices exist. People we trust, either because they have impressive degrees (not in nutrition), they make funny movies or because they have 100,000 followers on Instagram.

Just because you lost 50 pounds juicing, don't think that it's a good idea for everyone. I am incredibly happy whenever anyone has a health win... but it doesn't mean they know what's up. They figured out what works for them. Which is astoundingly awesome on its own -- just don't build them an "expert" throne.

A difference of opinion

I understand why this reductionism and absolute-ism happens. Having an authoritative voice tell you that gluten is the devil -- or that red meat is -- gives you a clear set of rules that makes healthy eating seem less ambiguous. Because when nutrition professionals give advice, we are always preaching moderation and balance.

It was also evident in the survey that nutritionists are rarely in 100 per cent agreement amongst themselves... and I know this to be true. Which is not exactly helpful for a confused public.

One of my greatest challenges as a dietitian is providing clear, unambiguous nutrition information when the very nature of human nutrition is one massive grey area. Published nutrition advice (including this post) is, by definition, intended for the masses. And this presents quite the problem, because good nutrition advice is individualized. So I might actually recommend juicing for one of my clients because it meets their needs... and tell another to avoid it because it isn't likely to work for them.

And foods aren't always made of the same stuff. Take granola for example. I would hazard a guess that the reason most nutritionists consider it unhealthy is because granola is historically thought to be laden with sugar and fat. So, eating a quarter cup of it is roughly akin to a scoop of Haagen Dazs. However, granola is often made from whole grains, which are healthy. And some granolas are actually low enough in sugar and fat that you can eat a reasonable portion and not be overdoing it.

Sushi is another great example. Is it healthy because it is low fat? Or unhealthy because you drown it in high-sodium soy sauce? Healthy, because you're eating fish? Or unhealthy, because you are eating a ton of sticky rice that spikes your blood sugar?

It depends on what your needs are and where you live on the spectrum of health. Swapping a burger meal for sushi is a bloody good choice. But if you're diabetic, I want you to avoid high-glycemic rolls in favour of sashimi. If you're pregnant, you have to watch the mercury content of fish, but if you're healthy and generally eat well, enjoy your damn sushi.

So, what the heck do I eat?

By its very nature, nutritional science will constantly evolve. Healthy will always be in the eye of the beholder, but the "what to eat question" is mostly unchanging. Cook for yourself using whole foods and you will be miles ahead of the masses.

And at the end of the day, you can always cling to the one universal truth: eat your veggies. Beyond that, ask your dietitian.

Pyramid imaged used with permission from Alexandria Hoare, The Dietitian's Pantry

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