Nutriton Labels
What is the most important part of a nutrition label?
When reading nutrition labels, the first and often largest number you see on the label is the calories. This must mean that this is the most important part of the label right? Actually, the ingredients section, in most cases located in the smallest font on the very bottom of the label, is where you should direct your attention. What you are eating is way more important than how much. In other words, quality over quantity. We have been told that "lower calorie foods are good and high calorie foods are bad." Unfortunately this has resulted in the manufacturing and consumption of unhealthy, low-calorie, processed foods.
So what are calories anyways?
Calories are a unit of measurement used to measure energy. Calories were originally calculated by burning a certain food and calculating how much it raised water temperature. Temperature change was used to calculate the amount of energy (calories) that food was worth. [1] Today, calories are calculated by the Atwater system (also known as the 4-9-4 system). This system calculates calories based on overall calories per gram of fat (9), carbohydrates (4), and protein (4). These numbers (4-9-4) were calculated by burning then averaging- therefore carbohydrates and protein contain an average of 4 calories per gram and fat contains an average of 9 calories per gram.
The Atwater System
This system for determining calorie content of foods, was created by Atwater over 100 years ago. While this has been the way that calories are determined in foods, recent research is showing that this system is not as accurate as we have accepted it to be. In fact, minimal research has been done to even test the accuracy of Atwater's coefficients, and studies, like this one by Janet A Novotny, Sarah K Gebauer, and David J Baer, found that the Atwater System had a 32% overestimation of their [almonds] measured energy content. [2]
So if this system is so inaccurate, why is it used to determine calorie content?
Believe it or not, this system is easy and simple- while food is not. Finding a system that can easily group complex food items is of course desirable, but is it practical? Lots of people are basing their daily food choices on inaccurately calculated calorie contents of foods- paying virtually no attention to what they are eating. I like to think about this like gas in a car. If I put a small amount of diesel gas in my premium car, it will run, but how well or for how long will it run? Who knows- but chances are not it will not run very well or for very long. But if I put a lot of premium gas in my premium car, chances are it will run better and longer. This is similar to our bodies. While there are uncontrollable factors that come into play (genetics, environment, etc.), for the most part, if we focus on eating more whole, healthy foods that fuel our bodies properly and less unhealthy processed foods that consist of empty energy and calories- our bodies are likely to run both better and longer.
The solution is simple
Food is like snowflakes- each piece and part being unique. This makes it extremely difficult, if not impossible, to calculate calories accurately. The solution? Focus more on what you are eating rather than the caloric number, and eat foods that do not have a nutrition label. Food is complex-bioavailability and content of foods vary depending the climate, soil, geographic location, and various other environmental factors used to produce that food. Because of this, the amount of fat, protein, and carbohydrates, as well as the mineral content will look different for each piece of food. Do not waste your time counting and stressing about calories- just eat real food.
References
[2] Novotny JA, Gebauer SK, Baer DJ. Discrepancy between the Atwater factor predicted and empirically measured energy values of almonds in human diets. Am J Clin Nutr. 2012;96(2):296-301. doi:10.3945/ajcn.112.035782
Comments