THE REAL FACTS ON NUTRITION FACTS
It’s great that people are becoming more aware of what they are eating and checking out nutrition labels. Whether you’re counting macros or have dietary restrictions, knowing where the numbers come from can help you make well-informed decisions that will benefit your body.
But just like people, nobody’s perfect; neither are nutrition labels.
So what are you supposed to do if nutrition labels aren’t 100% accurate?
Focus on consistently eating quality food, and often, those foods have limited ingredients! If you don’t like reading, you can stop now and focus on quality foods. If you want to know juicy details behind the methodology of food labels, then keep on reading!
Depending on the company, the nutrition label can be generated in two different ways. Smaller companies may rely on databases to get their nutritional label information for each ingredient (https://fdc.nal.usda.gov/). These databases are collections of analytical data for a range of ingredients. They may not be the most accurate as some ingredients are highly variable (for instance, fats and oils can vary widely based on the season and the region produced). Larger companies have to construct their labels based on analytical data that generally requires dozens of tests and thousands of dollars. Below are the top things we want to call out to you.
Fat isn’t just one thing – Most fat exists as what is called a triglyceride – 3 fatty acids that are all connected to a common glycerol backbone. These fatty acids are categorized by how large they are and if they are saturated fat or not. For labeling reasons, fat is broken down into two categories: Total Fat, which is everything you can extract from the product using alcohols and ethers, and the Specific Fats (Saturated, Trans, Omega-3, etc), which requires the same extraction but then breaks the fat down into the individual components.
Like fat, protein isn’t one thing – Whey proteins, casein, gluten, and plant proteins are all unique. However, one thing they have in common is they are rich in Nitrogen. By using acid or a small furnace, the product is broken down and the total Nitrogen is measured. Unfortunately, there are other things in food that contain Nitrogen that are not protein. To help with accuracy, some products may have a test for non-protein Nitrogen to correct this. Some companies have leveraged this fact by adding other ingredients that are high in Nitrogen to bring up their “protein content.” This isn’t a common practice as it is potentially dangerous for the consumer and usually results in legal action.
If you’re curious try Google searching “Melamine adulteration” for an example.
Carbohydrates are weird – There is no test for Total Carbohydrates, and so that value is more just the catch-all. The simplest way to think about it is to assume that carbohydrates are whatever is left after you remove the fat, protein, water, and minerals. A number of tests can measure individual sugars and fibers for labeling reasons, but the total carbohydrate values are based on an analytical assumption.”
When you measure any of these components, they don’t come out to round numbers. For instance, if the Total Fat is under 5g per serving then it is rounded to the nearest half gram. Why does this matter? It is just something to be aware of as you look at any products promoting zero-anything.
So what’s the takeaway here? Every value has a certain degree of error, but it is usually small, and the information is consistent overall. We recommend aiming for healthy eating choices like whole foods or foods with minimal ingredients, and that way a slight error on the label won’t make a difference.
Food Science M.S.