The fuzzy field of nutrition
What science leaves out
Nutrition is one of the most frustrating fields around. While certain regimes such as the Mediterranean Diet boost life expectancy and health outcomes, much of the underlying nutritional factors remain a mystery.
Of course, having a clear knowledge of what foods are most beneficial intuitively makes sense from a survival perspective. However, much of the dietary research that delineates good from bad has the unsettling habit of fluctuating from one year to the next.
For example, coffee was initially deemed good for us, then bad, then good again, then it caused cancer, and then it cured cancer. And coffee is not the only example. For years, fat was a dirty word. After World War II, studies established links between saturated fat and heart disease. Most experts advised people to reduce fat intake, not only to reduce heart disease risk, but also because fat contributes to weight gain as it has more calories per gram than protein or carbohydrate. The problem is people stopped eating healthy fats, like olive oil. Instead of controlling weight, decline in fat consumption triggered higher rates of overweight and obesity.
The reason why nutrition is a tough nut to crack is that we first have to know exactly what food people eat, and in what quantities, combinations, positions, etc. If this sounds impossible, that’s because it is. Fortunately, scientists devised “memory-based dietary assessment methods” (M-BMs) which survey people about their diet.
Unsurprisingly, when the scientists over at the Mayo Clinic looked into the M-BM, they found that the method was “fundamentally and fatally flawed” when it came to studying nutrition. They tried to be tactful about their findings by attributing failings of the M-BM to the unreliable nature of human memory, but the reality is people don’t forget, so much as imprint a “socially acceptable veneer” on their consumption habits (i.e. they lie).
Humans lie all the time, which is why a review of nutrition surveys found that around 60–65% of men and women report calorie intakes that are “not physiologically plausible.” Sadly this inaccurate data is what all food policy and dietary guidelines are based upon.
Award-winning nutrition journalist Gary Taubes argues that the reason nutrition fails as a science is because “the nutrition research community has failed to establish reliable, unambiguous knowledge about the environmental triggers of obesity and diabetes. Clinical uncertainty has opened the door to a diversity of opinions on the subject, of hypotheses about cause, cure and prevention, many of which cannot be refuted by the existing evidence. Everyone has a theory. The evidence doesn’t exist to say unequivocally who’s wrong.”
Based on findings, people should use common sense. Limit your intake of alcohol and drugs, try cooking your own food from natural ingredients, eat moderate and balanced portions, and reserve sugary processed foods for special occasions.
