We’ve been hearing a lot lately about the value of replacing processed foods – defined by the USDA as a food that has gone through any type of change to its natural state* with unprocessed foods. Any food that comes in a package is processed.**
It’s not as simple as processed vs unprocessed because even washing or packaging a food makes it technically a processed food. This means that the fresh fruit and vegetables you purchase in the grocery store are technically processed foods because they’ve been cleaned and refrigerated.
If we only ate unprocessed foods, we would either grow our own fruit and vegetables or purchase them from a farmer down the road – who hasn’t washed off any of the dirt. We also wouldn’t eat bread, crackers, oatmeal or other cereals, rice, cheese, plant milks, poultry, fish, meat, or almost any other food commonly found in our kitchens.
This is where the term minimally processed is helpful. Minimally processed foods are slightly altered to increase preservation, but the nutrient content hasn’t been changed. Examples include the whole foods you purchase in the grocery store: fruit, vegetables, nuts, seeds, brown rice, whole wheat flour, plain oatmeal, legumes, milk, and fresh or frozen poultry, seafood and meat without any seasonings or additives.
The opposite of minimally processed foods are ultra-processed foods formulated mostly or often entirely from substances extracted from foods. Ultra-processing makes these foods convenient for consumers and highly profitable for manufacturers. Examples of ultra-processed foods include sweetened yogurt, ice cream, pre-prepared breaded chicken and fish, packaged cookies and cakes, candy, chips, frozen meals, fast food, sausage, and hot dogs.
There are two sides to processed foods. On the one hand processing is helpful: adding important nutrients that are difficult to get in sufficient amounts to promote health, such as adding vitamin D to milk, and iron and folate to crackers, breads, and breakfast cereals. Canning fruit or vegetables without added salt or sugar preserves these nutrient-dense foods so that we can enjoy including them in our meals all year. Without this type of processing, we would only be able to eat locally grown fruit and vegetables when they’re in season. Can you imagine not enjoying 100% orange juice with breakfast, or making chili without canned tomatoes?
The other side of food processing is where health professionals are concerned: adding salt, sugar, unhealthy types of fat, food coloring and flavorings to foods. Ultra-processed foods are often specifically designed to increase our cravings for these foods – think about your favorite potato chip or crispy, salty snack; colorful sweet breakfast cereal often marketed to children (and that we continue to crave as adults); packaged cookies and sweetened beverages.
A study using data from the U.S. National Health and Nutrition Examination Survey (NHANES) found that ultra-processed foods provide about 60% of the total calories in our diet. Not only are ultra-processed foods often high in added sugars, fat and salt that increase inflammation and are associated with obesity, Type 2 diabetes, heart disease and some types of cancers; they also tend to be low in the important vitamins, minerals and fibers that are key for good health.
The Role of Processed Foods in Health:
A meta-analysis published in the February 14th 2021 issue of the British Journal of Nutrition found that people who consumed the most ultra-processed foods had 39% higher levels of obesity, 39% greater waist circumference, 102% lower HDL levels and 79% increase in metabolic syndrome. However, there was no association with higher blood pressure, blood sugar, or triglycerides – although all three of these are part of metabolic syndrome. The authors also found an increase in all-cause mortality, cardiovascular disease, cerebrovascular disease and depression in some of the studies they reviewed. For purposes of their review, they defined ultra-processed foods as products "created mostly or entirely from substances extracted from food or derived from food constituents with little or no intact food."
The authors suggest several reasons why ultra-processed foods have such a strong, negative impact on health:
- High amounts of added sugars and fats
- Low fiber content
- High levels of calories
- Compounds formed during processing that impact health.
- For example, acrylamide is a contaminant present in heat-treated processed food products.
- Acrolein is a compound formed when fat is heated.
- Both have been associated with an increased risk of cardiovascular disease.
- Plastic packaging that contains components identified as endocrine disrupters that associated with diabetes, obesity, neurological problems, immune system dysfunction, and some types of cancer.
- Qualities in the food that makes them easy to eat quickly and in large amounts before feeling satisfied
- Changes to the gut microbiome that promote inflammation, cardiovascular disease, and depression
For tips and tricks to help your audience include more unprocessed or minimally processed foods in their eating patterns, don't miss the post Strategies for Managing Processed Foods in Your Eating Pattern.
By Lynn Grieger, RDN, CDCES, CPT, CHWC
- Harvard T.H. Chan School of Public Health. Processed Foods and Health. https://www.hsph.harvard.edu/nutritionsource/processed-foods/ accessed 9-20-22
- Food, Nutrition & Fitness I: The Digestion Journey Begins with Food Choices 4 of 4 Compiled in 2018 by EduChange with guidance from NUPENS, Sao Paulo.
- Monteiro, C.A., Cannon, G., Lawrence, M., Costa Louzada, M.L. and Pereira Machado, P. 2019. Ultra-processed foods, diet quality, and health using the NOVA classification system. Rome, FAO.
- Steele EM, Baraldi LG, da Costa Louzada ML, Moubarac JC, Mozaffarian D, Monteiro CA. Ultra-processed foods and added sugars in the US diet: evidence from a nationally representative cross-sectional study. BMJ open. 2016 Jan 1;6(3):e009892.
- Chen, X., Zhang, Z., Yang, H. et al. Consumption of ultra-processed foods and health outcomes: a systematic review of epidemiological studies. Nutr J 19, 86 (2020). https://doi.org/10.1186/s12937-020-00604-1
- Pagliai G, Dinu M, Madarena MP, Bonaccio M, Iacoviello L, Sofi F. Consumption of ultra-processed foods and health status: a systematic review and meta-analysis. Br J Nutr. 2021 Feb 14;125(3):308-318. doi: 10.1017/S0007114520002688. Epub 2020 Aug 14. PMID: 32792031; PMCID: PMC7844609.
* Such as milling, heating, pasteurizing, cooking, freezing, drying, or adding salt, sugars, fats and other flavorings and additives.
** Such as bread, crackers, cereals, pasta, and rice as well as chips, cookies, ice cream and candy.
Stephanie Ronco has been editing for Food and Health Communications since 2011. She graduated from Colorado College magna cum laude with distinction in Comparative Literature. She was elected a member of Phi Beta Kappa in 2008.