As we know, processed foods come in many shapes and sizes. Some are minimally processed (i.e. fresh cut and packaged produce) and some are “ultra-processed” such as American cheese, frozen pizzas, and deli meats. While fresh fruits, vegetables, and meats are always better, nutritionally speaking, when eaten at peak freshness it is the classical nutritionist’s view that the health benefits start to diminish as they’re tampered with. From a classical nutrition standpoint, it is widely believed that processed foods, especially those that are ultra-processed, are merely empty calories. Often, these processed foods are perceived as, foods with little to no nutritional value, but still energy dense (meaning high in calories), which may very often be the case. If taking in fewer calories than we burn in a day leads to weight loss- which, let’s face it, is one of America’s main goals- then there is no room in our diets for low nutrient, energy dense (LNED) foods such as those that are ultra-processed.
It is a pleasure to have Anna Kathryn Colbert as a guest blogger this week. I am opening up this site to a divergence of views on processed foods for the next two weeks. Anna Kathryn is studying Nutrition at the University of Mississippi and was recommended to me by Dr. Georgianna Mann who teaches there in the Department of Nutrition and Hospitality Management. Georgianna took my Food Processing class as an undergraduate at the University of Georgia and has been the critical link between this blog and Don’t Eat the Pseudoscience. Anna Kathryn’s perspective is particularly timely in light of the publication last week of the NIH study on ultra-processed foods.
The third point of the 2015 Dietary Guidelines for Americans recommends that we, “limit calories from added sugars and saturated fats and reduce sodium intake.” While added sodium in ultra-processed foods have been our main focus for years now, an article published by the University of Kentucky states that the typical American diet is too high in solid fats and added sugars (SoFAs). So we have to ask ourselves, “What’s the common denominator?” It’s that many processed foods are high in saturated (solid) fats and added sugars as well as sodium. For example, in a 1 oz slice of American cheese there are 2.5 grams (13% of the recommended daily value) of saturated fat. In addition to its fat content, the same slice of American cheese also contains 200mg of sodium, which is about 8% of the recommended daily value. Although these percentages may not seem absurdly high, we must take into consideration the serving sizes and amounts of ultra-processed foods we consume. With the serving size being one slice of cheese, it’s easy for us to over indulge, using two or three slices for a grilled cheese sandwich then eating two sandwiches which then leads us to eating 4-6 slices of American cheese in a setting. While cheese isn’t always a bad thing, eating a diet primarily composed of processed foods is where these percentages of recommended daily values add up to become a problem, leading to obesity and an increased risk of chronic diseases such as diabetes and cancer.
A study published in BMJ Open notes that soft drinks account for 17.1% of US intake of added sugars. The same study states that nearly 90% of the added sugars in the American diet come from ultra-processed foods. With processed foods contributing such a significant percentage of added sugars to the American diet, it is necessary to avoid eating them as much as possible in order to ensure that we’re not exceeding the 2015 Dietary Guidelines for Americans’ recommendation to consume less than ten percent of calories per day from added sugars. Although the added sugars are apparent in many foods like sodas and snack cakes, there are hidden added sugars in other processed foods such as pasta sauces and salad dressings. This is where the danger of exceeding the recommendation of only eating ten percent of calories from added sugars comes in.
With obesity becoming more prevalent in the United States every year, traditional nutritionists propose that we may have processed foods to blame. There’s even some psychology behind this claim. Ultra-processed foods, high in sugars and fats, have been found to stimulate the release of dopamine, a neurotransmitter in the brain that’s often linked to pleasure and addiction. In this way, fast food companies are able to trap consumers in a vicious cycle of overconsumption of low nutrient, energy dense foods.
Due to the way fast-foods and other processed foods are manufactured, they’re low in fiber and other essential nutrients, making them easier to chew, swallow, and digest. By shortening the digestion time, we are able to eat more of these LNED foods than whole foods in a shorter amount of time. In addition to a shortened digestion time, it has also been suggested that ultra-processed foods affect hunger and appetite-suppressing hormones; therefore, leading us back to the cycle of overconsumption.
We are traditionally taught to avoid processed foods as often as possible in order to decrease risks of chronic illness, and while it is necessary to be cautious of what we’re putting into our bodies, when it comes to processed foods in our diets, it’s more about balance than sacrifice. Processing doesn’t always lead to disease and addiction. Chronic diseases arise when consumers’ diets and nutrient intake are severely out of balance from eating an excessive amount of nutrient-deficient foods and scarcely any nutrient-rich whole foods. There are ways of processing foods that don’t significantly alter its nutritional value and may even provide health benefits without adding saturated fats or breaking the Dietary Guidelines’ recommendations for calorie intake.
While I agree that foods with increased sodium, sugar, and saturated fat content should not make up one’s entire diet, there are many benefits to processing including: fermentation enhancing foods’ digestive benefits, soaking and cooking making some foods easier to digest, and freezing produce at peak freshness.
Fermentation, possibly the oldest way of processing foods, is a means of using yeast or bacteria to breakdown organic substances. This transforms the foods’ qualities and can make them easier for your body to digest, provide probiotic bacteria, and contribute to the overall health of gut which, in turn, could decrease the risk of some acute and chronic illnesses. According to Dr. Robert Hutkins, a food science researcher at the University of Nebraska, for some non-Celiac gluten sensitive people, they may find that they’re able to tolerate eating sourdough bread because of its extensive fermentation period.
Cooking and soaking some foods before eating may not seem to fall under the “processing” category as traditionally referenced/termed. However, it makes a major difference when preparing beans and grains which contain a protein called, lectin. When eaten raw, the lectins in beans and grains may cause significant gastrointestinal distress; however, when processed (i.e. cooked or soaked), the lectin content of these foods decreases and it frees up more good nutrients making them easier for your body to digest.
Freezing and canning preserves nutrients in produce for times when fresh fruits and vegetables aren’t available or a busy lifestyle doesn’t permit keeping fresh produce in the kitchen. Canned fruits (packaged in water or its own juice) and vegetables (low or reduced sodium) are also great to have on hand in the case of a natural disaster or other event where foods are without refrigeration for an extended period of time. Frozen and canned produce offer a nutritious, shelf-stable alternative to fresh fruits and vegetables since they’re packaged shortly after harvest at peak ripeness. Processing and preserving foods in these ways help ensure their nutrient value is maintained while stored. This belief was reinforced by a study conducted at the University of California, Davis. In the study, researchers found that the vitamin content of several popular fruits and vegetables had no consistent differences between the fresh and frozen fruits and vegetables in question.
Processing ranges from soaking beans to American cheese and everything in between; however, not all forms of processing are created equal. Ultra-processed foods often have low nutrient content and are energy dense while minimally processed foods aim to maintain and preserve nutritional value. With our on-the-go culture, it is easy to swing by a fast-food restaurant or vending machine for a quick bite, which is fine every now and then; however, our bodies need the nutrients found in whole foods in order to feel well, function well, and live well.
Anna Kathryn Colbert studied Nutrition and Dietetics at the University of Mississippi where she is now pursuing her M.S. in Food and Nutrition Services. With a background in leadership and foodservice, she currently works as a foodservice lab graduate assistant in the Department of Nutrition and Hospitality Management at UM. During her undergraduate years, Anna Kathryn became fascinated with food science through Dr. Georgianna Mann’s Experimental Foods course sparking further education and new research interests.
Next week: Processed food from a public health perspective
9 thoughts on “Processed food from a classical nutrition point of view by Anna Kathryn Colbert”
Thank you Anna Kathryn for your excellent article. I will be providing my view of ultra-processed foods and an analysis of the recent NIH article (https://www.cell.com/cell-metabolism/fulltext/S1550-4131(19)30248-7) in a series of posts next month.