Nutrition: an open letter

Man is the only animal that trips twice on the same stone.

I don’t usually write blog posts in english, but this time I think it’s worth the effort, because of a trend that I see is becoming popular through social networks, not much in Spain but more in UK and other countries.

We know for sure that nutrition science is still young and subject to many controversies. Precision Nutrition hit the nail recently with this article and infography. There are few absolute truths regarding the best way to eat healthy. The TIME covers related to fat consumption and health, became popular and are icons of the uncertainties in nutrition science. We know all the Ancel Keys and seven countries study thing, and diet-heart and lipid-heart hypothesis.  In 30 years, fats have been vindicated, from being the evil nutrient causing all of our health problems, to a healthy thing to eat daily.

Just 30 years away, but same issue: not the best public health messages.

And now, the scapegoat is sugar and carbohydrates. Some experts are leading this new trend, where sugar, and not fat, is the main public health concern in our shopping baskets. And it seems true that, the low-fat trend in the late seventies and eighties, led to the development of many processed foods low in fat, but high in sugar (and later in “healthy” polyunsaturated vegetable oils) in order to make them palatable. This may have lead astray the idea of a low fat diet to prevent cardiovascular diseases and obesity.

But to me, all this focus on certain macronutrients, will just lead us to the same dead end (pun intended). It is what Gyorgy Scrinis , Michael Pollan and others have coined as Nutritionism (the idea that the nutritional value of a food is just the sum of all its individual nutrients). To me, this approach can only end up in a mess again, if we now swing the pendulum to the other end of the macro triad.

Basing public health messages on nutritionism can only end up in a mess, again

The average buddy reading the headlines, newspapers and social networks, can very easily be misled and confused, after all the contradictory messages he may find. If a strong statement against carbohydrates and in favour of fat is made, he may easily follow blindly. And you, fellow nutritionist or health professional know well that it is not that simple.

I agree fats per se are not evil. Also, I do not think all fats are equal, not even between saturated (the focus now) / mono- or polyunsaturated, but also inside each class, different single fatty acids can have different effects. Talking about just fats or even saturated fats is an oversimplification (chemist bias at work). But as many of the supporters of the saturated fats are good claim, food matrix IS important.

On the other hand, low carb diets have become popular, and many of the fats-are-good team of supporters are also rallying against sugar and carbohydrates. But this time, unfortunately, it seems that the food matrix is NOT important. And I think of course this is a double mistake. Because same as we cannot regard the same a cut of processed meat versus a cut of good unprocessed grass-fed meat, you cannot compare a loaf of white processed flour bread to let’s say a sweet potato.

Food matrix is very important, as is diet as a whole

Food matrix matters. Food quality matters. And it matters much! Because, no matter how many epidemiological or clinical trials we carry out, there are living examples of populations living a healthy life, with low prevalence of the so called western diseases, with high fat, high protein, or high carbohydrate diets. But all of them have one thing in common: being whole-food based, with absence or very low consumption of processed foods. Of course, not only nutrition has a say here, and the whole lifestyle is responsible for their good health. But they are the black swans we need.

Focusing on just macronutrients we are falling again in the same trap. Let’s just start by sending a strong message to follow a diet low in processed food, and rich in whole foods. This is the easiest message to follow: eat real food. After that, let’s fine tune that, and we agree the 55/15/35 fixed macro rule is a thing from the past. But let’s not make that the focus of our public health messages, because we know it did not work, and it will not work again.

Additionally, apart from improving our messages and communication skills (working along the mass media if possible) we need to reconsider the nutritional research strategy as a whole. I completely agree with John Ioannidis, that more huge epidemiological studies, or small clinical trials, will not shed new light. We need answers, and we need a systematic approach, to iteratively solve the burning questions we have been chasing for years. Without cooperation and joint efforts, that will be not possible.

I just would like to suggest the #stopnutritionism hashtag, when you see that kind of messages around. Let’s try not to trip twice on the macronutrient stone.




Un comentario en “Nutrition: an open letter

Los comentarios están cerrados.