As a doctor who treats gastrointestinal diseases and diagnoses colon cancer, this is the stuff that keeps me up at night. The phrase,’ American as apple pie,’ once had meaning. Considering the staggering amount of processed foods we eat—’American as soy lecithin and high fructose corn syrup,’ is probably more appropriate.
Processed foods are so common in the American diet, most people don’t know how to recognize them. I once fell into this category. Years ago when I was a freshman taking organic chemistry at the University of Michigan (Go Blue!), gaining an understanding of the chemical nomenclature of ingredients listed on food labels excited me. Now, I just feel depressed when I reflect on this. Having a basic understanding of what you’re eating shouldn’t require a class in organic chemistry at one of the country’s best public institutions. This knowledge should be accessible to anyone with a high-school education. The problem is that most of our calories come from food that’s chemically engineered instead of raised or farmed.
So, how can the average person identify processed foods?
In this post, we define processed foods, break down the categories of processed foods, and share 9 reasons why processed foods are bad for your health.
How do you define processed foods?
The USDA defines processed foods as:
Any food other than a raw agricultural commodity, including any raw agricultural commodity that has been subject to washing, cleaning, milling, cutting, chopping, heating, pasteurizing, blanching, cooking, canning, freezing, drying, dehydrating, mixing, packaging, or other procedures that alter the food from its natural state. Processing also may include the addition of other ingredients to the food, such as preservatives, flavors, nutrients, and other food additives or substances approved for use in food products, such as salt, sugars, and fats (2).
The problem with this definition is that it labels a chopped carrot and dill pickle flamin’ hot chips both as processed foods. Clearly cutting a carrot and dill pickling, flamin’ hotting, and deep-frying potatoes in hydrogenated oils are two different things. Hence, I prefer the definition that Dr. Robet Lustig put forth in his scathing editorial on processed foods in JAMA (3).
Processed food is defined by 7 food engineering criteria; it is mass produced, is consistent batch to batch, is consistent country to country, uses specialized ingredients from specialized companies, consists ofDr. Robert Lustig
pre- frozen macronutrients,stays emulsified, and has longshelf life or freezer life.
His definition reflects the industrial aspects of processed foods. On the other hand, the USDA’s definition is too broad. According to the USDA, anything that isn’t raw and uncut can pass as processed food. If I use the USDA’s definition when advising patients to cut back on processed foods, I’d literally have to tell people to not clean, wash, or cut their foods. That’s R. Kelly and Jussie Smollett levels of ridiculous. As such, researchers have recognized that there are various degrees of food processing. Hence, researchers created criteria for categorizing processed foods by the extent of their processing—the NOVA classification (4).
Have you heard of the NOVA classification for categorizing processed foods?
It’s ok if you haven’t—most doctors don’t even know about this stuff. The classification has 4 categories:
- unprocessed or minimally processed foods
- processed culinary ingredients
- processed foods
- ultra-processed foods
Advocates for using the NOVA classification astutely highlight that,
Conventional food classifications no longer work well. They usually group foods and foodstuffs in terms of their botanical origin or animal species and according to nutrients they contain. In this way they often group together foods that have different effects on health and disease. So ‘cereals and cereal products’ often group whole grains together with sugared ‘breakfast cereals’ and cookies (biscuits), and ‘meat and meat products’ often group fresh chicken together with ‘nuggets’. This side- lining of food processing has serious consquences, as shown below.
Let’s dig a little deeper into the NOVA classification’s categories.
1. Unprocessed or minimally processed foods
Foods that are unmodified or modified by techniques you can actually perform in your kitchen or at a restaurant fall under this category. Cutting, chopping, baking, frying, heating, freezing, et cetera, are all examples of minimal processing.
2. Processed culinary ingredients
This category includes foodstuffs like olive oil, butter, sugar, spices, and salt. Foods in this group come from unprocessed foods or nature, but are modified by pressing, grinding, drying, refining, and milling. For instance, ground ginger in a jar obviously comes from ginger— ginger ale is a different beast altogether.
3. Processed Foods
These are foods that are preserved, have 2-3 ingredients, but are still recognizable as modified versions of their original state. For instance, canned peaches in syrup or sardines canned in olive are good examples. Fresh artisan breads, cheese, and jarred pickled beets also fall into this category.
4. Ultra-processed foods
Foods in this category are
Ultra-processed foods include pop, packaged sweets, reconstituted meat products, pre-prepared frozen dishes. Foods with this level of processing aren’t just modified foods—they are chemically engineered formulations made mostly from additives, preservatives, and substances derived from natural foods.
These are the foods you find at gas stations, the center aisles of supermarkets, and commonly in the frozen food section. Ultra-processed foods contain ingredients that you can’t buy at your local supermarket (even Whole Foods). Try buying BHT and yellow #5 at your local Piggly Wiggly.
Here’s a list of ingredients, additives, and preservatives commonly found in ultra-processed foods.
|hydrogenated oils||flavor enhancers|
|soy protein isolate||maltodextrin|
|emulsifiers||high fructose corn syrup|
|anti-caking agents||food coloring|
So, what else is wrong with ultra-processed foods? Here’s 9 issues you should know about.
As previously mentioned, Dr. Robert Lustig provided an excellent definition of processed foods. He also highlighted 9 reasons why they are not good for us.
rocessed foods lack fiber.
Fiber is one of the keys to avoiding colon cancer and cardiovascular disease. In fact, I’d argue that if you are trying to live a long and healthy life, you need some fiber. Most Americans lack fiber primarily because of our dependence on ultra-processed foods. Trust me, it’s no coincidence that constipation is the number one reason that people come to see me in my
2. Too few omega-3 fatty acids.
Omega-3 fatty acids have anti-inflammatory properties. They are the reason why everyone’s excited about flaxseeds, chia seeds, and fish oil. Chronic inflammatory diseases are prevalent in the U.S. The lack of Omega-3 fatty acids in ultra-processed foods probably isn’t helping anything.
3. Too many omega-6 fatty acids.
Omega-6 fatty acids may be pro-inflammatory. Not all inflammation is bad. You need some inflammation to fight off infections. However, too much inflammation (or chronic inflammation) can lead to chronic diseases such as autoimmune disease and cardiovascular disease.
Our current diet is extremely high in omega-6 fatty acids. This is likely due to the high amounts of soybean oil and our diet. It is not clear if inflammation is due to omega-6 fatty acids by themselves, or if the real culprit an imbalance between omega six and omega-3 fatty acids.
Anthropological studies suggest that the ratio between omega 6 and omega-3 fatty acids was 1 to 1 in ancient man (5). Today, for the average person, the ratio is about 16 to 1. Processed foods are one of the reasons for this imbalance since they are frequently contain added oils rich in omega-6 f
4. Too few micronutrients
Ultra-processed foods typically are low in vitamins and minerals. As such, processed foods do not provide much when it comes to promoting health. Some micronutrients are may have anti-cancer properties. Since 60% of the average American’s calories come from processed foods, the elevated rates of cancer in the United States are not surprising.
5. Too many trans fats
Trans fats are artificially occurring fats that lengthen the lifespan of various food products. Trans fats also remain mostly solid at room temperature. Not too long ago trans fats were seen as a healthy
6. Too many emulsifiers.
Emulsifiers keep fat and water from separating. You can find them in processed foods such as ice cream, salad dressings, and other creamy products.
Eggs and mustard are natural emulsifiers. The emulsifiers in processed foods include unnatural
7. Too many nitrates
Recently, the W.H.O. listed foods high in nitrates such as hot dogs and processed meats as possible carcinogens, chemicals that promote the formation of cancer. The W.H.O. never suggested that one slice of bacon causes colon cancer. However, they did highlight that frequently consuming foods processed with nitrates over extended periods has been associated with cancer.
Nitrates are used to preserve meat. Hence, the beef jerky that you see in the supermarket checkout aisle doesn’t need to be refrigerated. However, if you left a piece of untreated beef in the checkout aisle, it would spoil in a couple of hours. If you frequently consume jerky or cured meat, check the ingredients section to see if they use nitrates as a preservative.
8. Too much salt
The salt struggle is real. I’ve seen many people, even seemingly healthy ones, with extremely high blood pressure. Before you blame high blood pressure on
9. Too much high fructose corn syrup.
High fructose corn syrup is the R Kelly of food ingredients. It sounds nice, but it’s actually terrible for you. High fructose corn syrup became popular amongst manufacturers in the 1970s as a cheaper alternative to sugar. Although controversial, many people have blamed the obesity epidemic over the past 40 years on the abundance of high fructose corn syrup.
So, what is high fructose corn syrup?
It is essentially corn syrup with extra fructose. It is the poster child for processed foods because it is an industrial ingredient that you cannot buy at your local supermarket. But, it’s prevalent in a significant amount of food that you can buy at the supermarket. If you are eating anything that lists high fructose corn syrup as an ingredient, it’s an ultra-processed food.
What’s the bottom line?
- There are varying levels of food processing.
- Ultra-processed foods are the most processed of all the processed foods.
- When people say processed foods are bad, they are really referring to ultra-processed foods.
- Eat foods closer to their natural form.
- Follow The Doc’s Kitchen
- Baraldi, L. G., Steele, E. M., Canella, D. S., & Monteiro, C. A. (2018). Consumption of ultra-processed foods and associated sociodemographic factors in the USA between 2007 and 2012: evidence from a nationally representative cross-sectional study. BMJ Open, 8(3), e020574. http://doi.org/10.1136/bmjopen-2017-020574
- Cereals 17 Symposium: Introductory Brain Teaser for the Cereal Chemist—How Do We Categorize Processed and Ultraprocessed Foods? (n.d.). Cereals 17 Symposium: Introductory Brain Teaser for the Cereal Chemist—How Do We Categorize Processed and Ultraprocessed Foods?
- Lustig RH. Processed Food—An Experiment That Failed. JAMA Pediatr. 2017;171(3):212–214.
- Michael J Gibney, Ultra-Processed Foods: Definitions and Policy Issues, Current Developments in Nutrition, Volume 3, Issue 2, February 2019, nzy077, https://doi.org/10.1093/cdn/nzy077
- Evolutionary aspects of diet, the omega-6/omega-3 ratio
andgenetic variation: nutritional implications for chronic diseases. (n.d.). Evolutionary aspects of diet, the omega-6/omega-3 ratio andgenetic variation: nutritional implications for chronic diseases.
- Trans fats in America: a review of their use, consumption, health implications, and regulation. (n.d.). Trans fats in America: a review of their use, consumption, health implications, and regulation.
I am a physician and trained chef. I specialize in gastroenterology and nutrition. Currently I work as the Associate Director of Adult Nutrition at the University of Chicago.