In Defense of Food by Michael Pollan, January, 2008, Penguin Press, p 244, US$21.95, ISBN: 978-1-59520-145-5
As mentioned in the first part of my review of “In Defense of Food”, nutritionism is not same as nutrition, which is a science, but it is the ideology surrounding food as only a supply of nutrients. The term was defined by Gyorgy Scrinis in 2002:
“[…] namely, that we should understand and engage with food and our bodies in terms of their nutritional and chemical constituents and requirements – the assumption being that is all we need to understand.”
Foods are used to promote physical health with some nutrients being “good” and others being “bad”. In the nineteenth century the German organic chemist Justus von Liebig promoted meat as it was high in protein. For any British readers, Von Liebig meat extract company developed OXO. Protein was the master nutrient as eating more protein lead to bigger and, obviously, healthier people. However, for every “good” nutrient we need a corresponding “bad” nutrient, hence leading to fads of anti-fat, anti- carbohydrate, or anti-protein.
The biggest problem with nutritionism is that it is only based on nutrients that can be measured. At first this meant the macronutrients protein, fat and carbohydrates. As analytical technology improves, there is more concern about food components, both good and badthat are present in smaller and smaller amounts. This explains the recent interest in phytochemicals and in potential carcinogens such as heterocyclic amines and acrylamide.
The increase awareness of food as a supply of nutrients lead to the development of dietary guidelines and this, in turn, lead to the golden age for food science [technology]. I do agree that it is ridiculous that processed food items, such as Cheerios, can have a health claim while fresh produce, such as carrots, do not. As Pollan’s biggest criticism of science is that food animals are now breed to be leaner; ignoring that fact that before the 1980s, beef and pigs were originally breed to be fatter, I do contest that he is being selective with the science being used.
For example, Pollan quotes extensively from an article by Frank et al (2001)* but with this quote I have doubts about their nutritional knowledge:
“Surprisingly, there was little direct evidence linking high egg consumption and increased risk of CHD – surprisingly [Pollan goes on to write], because eggs are particularly high in cholesterol.”
This should not be surprising to any nutritionist. I was taught in the 1980s that dietary cholesterol has NO bearing on serum cholesterol levels unless you suffer from some form of hyperlipidaemia. Thus, dietary cholesterol is less of a risk than dietary fat.
Additionally, there is a problem with Pollan’s critique of dietary guidelines and the food industry, some of which I addressed earlier. Pollan is justifiably very critical about trans fats as they appear to have turned out to be more harmful that traditional saturated fats, but like Taubes, he is selective in the scientific literature he uses to discuss the low-fat diet. The biggest criticism I have of Pollan and Taubes is that they IGNORE both calories and physical activity. This may be a fault of the dietary guidelines; until the latest version of the food pyramid, exercise was not mentioned in relationship to diet. Additionally, Pollan ignores the increase in portion size and that effect on diet. Ask any European visiting the US for the first time – portions here are huge, but my experience tells me that you soon adapt to this and start feeding yourself more at home too.
The biggest problem, in my opinion, with the low-fat dietary theory is that people are now scared of fat and think they should not eat any. They eat low fat everything without considering the taste. It would be better to eat smaller amounts of high fat food than a large portion.
According to Pollan the biggest problem with nutrition is that it is, like most sciences, a reductionist science. Understanding how our body responds to food and nutrients is enormously complex. Most nutrition studies isolate one part of the diet; whole grains or fiber, for example; and study its effect on one bodily function; for example, weight or serum cholesterol; without considering either the whole diet or the whole body. However, changing your intake of whole grains may alter your intake of fruit and vegetables.
I do agree with Pollan’s conclusion:
“Now, all this might be tolerable if eating by the light of Nutritionism made us, if not happier, then at least healthier. That is has failed to do. Thirty years of nutritional advice have left us fatter, sicker, and more poorly nourished. Which is why we find ourselves in the predicament we do: In need of a whole new way to think about eating.”
Part three of my review, Part II: The Western Diet and Diseases of Civilization, to follow.
Frank et al (2001) Types of Dietary Fat and Risk of Coronary Heart Disease: A Critical Review. Journal of the American College of Nutrition. 20(1) 5.