Whether someone has a family of five to feed or is just a hungry college student, it’s common to have a shopping list to make grocery store runs short and sweet. Similarly, all of the food on the shelves has its own list — sometimes just glanced at quickly or ignored entirely — boasting its nutritional value and ingredients.
Believe it or not, these food labels also have a larger part in the working nutritional sciences of human bodies, according to registered dietitian nutritionist Tara LaRowe.
“The food label definitely has a connection with the current science, and it’s supposed to be an educational tool for consumers,” LaRowe said. “[It] does change significantly based on science.”
Though people are now able to see the ingredients and nutrition facts of any food, these numbers have much more significance biologically rather than being “just numbers” on the back of a box.
STEM students with disabilities face extra barriers in earning degree
Senior Elizabeth Tan studying food science recognizes that calories, specifically, are a bit harder to understand beyond their numerical value. Because when people consume calories, what they actually consume is a type of heat energy.
“It’s the energy needed to raise the temperature of 1 kilogram of water by 1 degree Celsius,” Tan said. “It’s not a physical thing — it’s the energy measurement.”
UW associate professor in the Department of Nutritional Sciences Beth Olson said understanding food labels can be straightforward, even if there’s a lot of biochemistry behind it all.
Energy comes from the chemical bonds in the food people consume. During mechanical processes, like chewing and swallowing, enzymes react with the food as it travels from the mouth into the gastrointestinal tract, stomach and finally bloodstream, Olson and Tan said. Every macronutrient, such as carbohydrates, proteins and fats, has its own calorie content and proper proportions in a diet for optimal bodily function.
How increased lightning strikes from climate change alter world’s forests
In every gram of carbohydrates and proteins, there are four calories — in fats there are nine, Olson said. Of these nutrients, 50-60% of our calorie intake daily should come from carbohydrates, 10-25% from proteins and 30-35% from fats, LaRowe said.
Other than accounting for calories as energy, the body must break down these macronutrients so they can enter the circulatory system. Fat, for example, presents a challenge for the body to break down, Olson said, as they tend to form globules in the body which the body then needs to emulsify.
There are also different types of fats to consider, each with different properties.
Saturated fats have a rigid chemical structure, so they’re harder for the body to process and thus people shouldn’t consume them in excess. Since there are no points of unsaturation in their chemical structure, these fats are solids at room temperature and thus more rigid and harder on the digestive tract, Olson said. Examples are animal fats from meat and butter. They also can contribute to plaque buildup, according to Tan.
Wisconsin Department of Health prepares for updated COVID-19 booster to become available
Other fats, like monounsaturated or polyunsaturated fats, can have beneficial impacts on health and are helpful toward preventing chronic diseases, Olson said. These fats can come from fatty fishes, like salmon and herring.
Much of the body’s inability to process rigid fats is due to the chemistry of fats not mixing well with the body because it is mostly made up of water. That is, in comparison to solid foods and fats, water, tea and juices are easy to digest, Olson said.
This is not to say one should only consume liquids or foods with a high water content, such as fruits and vegetables, because they are easy to digest and have lower calorie content. According to Olson, these foods, though healthy, provide less energy density than solid and whole foods. The body has a large requirement for a variety of solid foods in a diet and cannot survive on one nutrient alone, nor rely on itself to create nutrients.
“There’s nutrients we need to function. We can make some of them — those are nonessential nutrients,” Olson said. “Then there are essential nutrients, meaning [we] can’t make these, like some amino acids.”
Current dietary studies are looking to validate the body’s need for a variety of foods because just like many scientific disciplines, lots of mysteries remain. Some of these ingredients can be beneficial, too, even if the body doesn’t have a specific requirement for it, Olson said.
It’s also possible for the body to alter its biochemical food processes according to a certain diet.
“The microbiome — all the microbes in your gut — are influenced by where you live, the people you live with and individual diet,” Tan said. “If you become vegan, you’ll start losing the microbes that are beneficial for digesting meats because they aren’t being used and are being outcompeted by other plant-digesting microbes.”
Though it’s just a panel of numbers and words on the surface of food packaging, there is a significant amount of science going on inside the body. It might not be second nature for some to take the time to read and understand nutrition labels, but the body knows how to interpret what enters its digestive tract.
