Nowadays, foods are processed more than ever before. While this makes them last longer, are there any dangers involved with these types of foods? How do you know which processed foods are okay to eat and which you should avoid? What risks are associated with consuming these foods frequently?

Our food is dominated by the availability of relatively cheap and accessible ultra-processed foods. These foods are constantly being marketed, which has led to a dramatic increase in their consumption globally. In fact, they now account for 25–60% of a person’s daily energy intake. Researchers at the University of Chapel-Hill found that over 60% of the food purchased annually in America is highly processed. Another study using data from the U.S. National Health and Nutrition Examination Survey found that ultra-processed foods make up about 60% of total calories in the American diet. Why are they so horrible for you?

What Is Processed Food

It’s not surprising that the term “processed food” causes confusion because most foods are processed somehow. When you cook, bake, or prepare food, you’re processing it. Not all processed foods are bad for you. Some foods are fortified with nutrients to prevent deficiencies and their related health problems, such as cereal fortified with vitamin D.

The U.S. Department of Agriculture (USDA) classifies processed food as one that has undergone any change to its natural state. This means taking any raw agricultural commodity and subjecting it to washing, cleaning, milling, cutting, chopping, heating, pasteurizing, blanching, cooking, canning, freezing, drying, dehydrating, mixing, packaging, or other procedures. However, it can also include the addition of other ingredients, like preservatives, flavors, and other food additives, such as salt, sugars, and fats.

The Institute of Food Technologists includes additional processing terms like storing, filtering, fermenting, extracting, concentrating, microwaving, and packaging. When you look at it this way, virtually all foods would be classified as “processed” to some degree. This is why it’s helpful to differentiate between the various versions.

One useful system is NOVA which was introduced in 2009. It’s recognized by the World Health Organization (WHO), the Food and Agriculture Organization, and the Pan-American Health Organization. It’s not currently used by the USDA because it has been criticized for being too general in its classification of certain foods and doesn’t provide comprehensive lists of specific foods in each category, so the consumer has to guess where a food is supposed to go. Most experts can agree that there are two main classifications.

Minimally processed, or unprocessed, foods include the natural edible food parts of plants and animals. Typically, these foods have been slightly altered to preserve them but not enough to substantially change the nutritional content. The process allows the food to be stored for an extended amount of time while remaining safe to eat.

Examples are cleaning, removing inedible/unwanted parts, grinding, refrigeration, pasteurization, fermentation, freezing, and vacuum packaging. Many fresh fruits, vegetables, whole grains, nuts, meats, and milk fall into this category. Some processed culinary ingredients come from minimally processed food by pressing, refining, grinding, or milling. These aren’t eaten independently but are used to prepare other minimally processed foods, such as oils from plants, seeds, and nuts, or flour and pasta from whole grains.

Some foods from the previous group have salt, sugar, or fats added to them, making them processed foods. However, these foods usually have two or three ingredients and can be readily eaten without further preparation. Some canned fruits and vegetables, some cheeses, freshly made bread, and canned fish fall into this group.

Ultra-processed foods, or highly processed foods, are low in dietary fiber and vitamins while being high in sugar, artificial ingredients, refined carbohydrates, and trans fats. They tend to have added chemical flavoring agents, colors, and sweeteners, which contain little nutritional value. Additives, like emulsifiers, preserve the texture of foods (ex. preventing peanut butter from separating).

Other elements of processing include keeping desirable sensory qualities of food (ex. flavor, texture, aroma, appearance); and increasing convenience in preparing a complete meal. Some examples of ultra-processed foods are frozen/ready meals, baked goods (ex. pizza, cakes, and pastries), packaged bread, processed cheese products, breakfast cereals, crackers/chips, candy, ice cream, instant noodles/soups, reconstituted meats (ex. sausages, nuggets, fish fingers, and processed ham), and sodas/other sweetened drinks.

Processed Foods & Unhealthful Nutrients

Processed foods tend to contain many substances that aren’t good for you. One of the main things is added sugar, which usually is in the form of high fructose corn syrup. The problem with added sugar is that it doesn’t provide any nutritional content. Instead, it has high amounts of calories. Not only that, but it also doesn’t naturally occur in food, which means it has to be put in manually. Sweetened beverages, such as sodas and sports drinks, are a particularly significant source of it. Research shows that regularly consuming large amounts of added sugar are linked with many health conditions, like obesity, metabolic syndrome, type 2 diabetes, and inflammatory diseases.

While carbohydrates are an essential component of any diet, the type you consume makes all the difference. Sugars are a form of carbohydrates, and when consumed in excess quantities, they must be stored in the body, typically as fat. Carbs from whole foods provide far more significant health benefits than those that are refined. Your body breaks down refined carbohydrates quickly, causing rapid increases in blood sugar and insulin levels. When these levels then crash a short time later, you experience low energy and food cravings. As a result of its impact on the body, refined carbs are linked with an elevated risk for type 2 diabetes. Highly processed foods often have large amounts of refined carbohydrates.

Processed foods are typically low in dietary fiber because it’s lost during their development. Dietary fiber is essential for many reasons. It can slow the absorption of carbohydrates and helps you to feel more satisfied with fewer calories. It has prebiotic properties as well. The other issue is the way manufacturers make processed foods. They’re designed to be very easy to chew and swallow. Without fiber, your body takes less energy to digest ultra-processed foods than whole or less processed foods. All of this combined means you’ll eat more of these products in shorter periods.

Ultra-processed foods are frequently high in unhealthy, cheap fats. Manufacturers make artificial trans fats by adding hydrogen to liquid vegetable oils, which renders them more solid. Trans fats increase inflammation in the body, raise levels of low-density lipoprotein (bad” cholesterol), and decrease levels of high-density lipoprotein (“good” cholesterol). Eating these fats is associated with an increased risk of heart disease, stroke, and type 2 diabetes. A 2019 study found that a 2% increase in energy intake from trans fats is linked with a 23% increase in cardiovascular risk.

Some of the ingredients listed on the back of processed food packaging are unrecognizable substances. Some are artificial chemicals added to make the food more palatable. Other chemicals are preservatives, artificial coloring, chemical flavoring, and texturing agents.

  • Preservatives generally promote safety by preventing the growth of mold and bacteria. Some examples are ascorbic acid, sodium benzoate, potassium sorbate, and tocopherols.
  • Emulsifiers are agents that prevent the separation of liquids and solids, including soy lecithin and monoglycerides.
  • Thickeners add texture, such as xanthan gum, pectin, carrageenan, and guar gum.
  • Colors are used to have the food be a particular color like artificial FD&C Yellow No. 6 or natural beta-carotene to add yellow hues.

Sometimes, processed foods contain dozens of additional chemicals that are not listed on their labels. For example, “artificial flavor” is considered a proprietary blend, so manufacturers don’t have to disclose what it means; it’s usually a combination of chemicals.

Health Problems from Processed Foods

Consuming significant portions of processed foods has been linked to an increased risk of a wide variety of health problems, such as obesity, high blood pressure, elevated cholesterol, cancer, and depression. Two extensive studies found that people who consume many ultra-processed foods are more likely to develop heart disease and die sooner than those who eat foods in their original form. The studies were published in The British Medical Journal (BMJ). It’s important to note that they relied on participants to recall what they ate accurately. This can be unreliable.

Another consideration is the potential for many factors that lead people to buy ultra-processed foods, such as poverty or limited education, which can independently contribute to heart disease and premature death. Also, both studies were observational, so causality can’t be established.

The first study was the Seguimiento Universidad de Navarra (SUN), based in Spain, and evaluated possible associations between ultra-processed food intake and death risk from any cause. The study included 19,899 Spanish university graduates (7,786 men; 12,113 women) between 20 and 91, with an average age of 38. Participants completed a 136-item dietary questionnaire and were asked about their eating habits every two years from 1999 to 2014. During that period, 335 participants died.

Individuals who ate the most processed foods (more than five servings a day) were more likely to be obese, smokers, frequent snackers, regular television watchers, and have medical conditions (ex. cancer, diabetes, high blood pressure, high cholesterol, and depression). According to the data, eating more than four daily servings of ultra-processed foods leads to a 62% higher risk of premature death than eating little (less than two servings) or none of these foods. For each additional serving, mortality risk increased by 18%.

The other study, the NutriNet-Santé stud, looked at ultra-processed foods and cardiovascular disease risk. It included 105,159 French adults (21% men; 79% women) with an average age of 43. Participants completed an average of six 24-hour dietary questionnaires to measure the intake of 3,300 different food items. Foods were grouped according to the degree of processing, and disease rates were measured over a maximum follow-up of 10 years (2009-2018).

During the study, a total of 1,409 first-time cardiovascular disease events, such as heart attacks and strokes, transpired. Those who ate the most processed foods were 12% more likely to have cardiovascular disease, 13% more likely to have coronary heart disease, and 11% more likely to have cerebrovascular disease. The data demonstrates that eating 10% more ultra-processed foods was associated with a 10% increase in the risks of all three disorders. On the other hand, researchers discovered a significant association between unprocessed or minimally processed foods and lower risks of all reported diseases.

Another major concern with processed foods is obesity. It’s well known that dietary sugar contributes to this disease, leading to a host of other chronic diseases. Since highly processed foods are loaded with added sugar, this makes them a prime culprit. The problem is you may not know that you’re ingesting all this sugar because there are as many as 50 different words used to list sugar in foods. Consumption of sugar triggers a sense of pleasure and craving within the brain that research has found is comparable to drug addiction.

One study of 20 healthy adults confined in a lab under close surveillance for 28 days had interesting results. Half of the participants received a diet of ultra-processed foods, including white bread, lunch meats, cheese slices, chips, and artificially sweetened diet drinks. The other half received the exact same number of calories, sugars, fiber, fat, and carbohydrates per meal, but only in the form of unprocessed and minimally processed foods. This included things like beef tips with broccoli, brown rice, apples, and salad. The study participants could eat only the provided food but didn’t have to clean their plates.

At the end of the study, those in the ultra-processed group had consumed about 500 calories per day more and gained 2 pounds. The other group actually lost 2 pounds. According to the 2015-2020 Dietary Guidelines for Americans, added sugars should be limited to no more than 10% of daily calories or about 12 teaspoons. It’s important to note that the average soft drink can contain approximately ten teaspoons.

Metabolic Syndrome is another concern related to processed food. This condition is defined as a group of risk factors that can lead to heart disease and type 2 diabetes. It has five risk factors and is diagnosed when a person has three or more of them. The risk factors are having an increased waistline with abdominal obesity, elevated triglycerides, low HDL cholesterol levels, high blood pressure, and high fasting blood glucose. If you need medication to treat any of these, it’s also considered a risk factor. The large quantities of sugar in highly processed food is the main culprit of metabolic syndrome.

Inflammatory bowel disease (also known as Crohn’s disease or ulcerative colitis) results from consuming emulsifiers, which are found in nearly every processed food product. The emulsifiers used in processed food are similar to those found in your household soaps or detergents because their primary function is to allow water and oil to stay mixed. These cause gastric problems because the bacteria affected by them make up the protective mucus layer that usually separates microbes from your intestinal wall.

Emulsifiers in your stomach act the same as how a detergent works to remove dirt. When your body doesn’t have its natural protective mucus, it leads to an inflammatory response causing the diseases. Autoimmune diseases are the result of the body’s immune system attacking its own cells. While there are over 100 different types, the more common ones are type 1 diabetes, lupus, multiple sclerosis, rheumatoid arthritis, Crohn’s disease, and Hashimoto’s thyroiditis.

It’s estimated that 70% of your immune system is located in your gut because it needs to protect you from all the environmental toxins that travel through your digestive tract. You have a special layer of cells, epithelial cells, whose function serves as a protective membrane. These cells are joined together by tight junctions to keep them bonded together and strengthen their defense barrier. Problems arise when these junctions become compromised, allowing the body to be exposed to harmful toxins. This is usually referred to as “leaky gut.”

Research has shown that seven common additives regularly found in processed foods can damage these tight junctions. The seven additives are glucose, salt, emulsifiers, organic solvents, gluten, microbial transglutaminase, and nanoparticles.

Higher rates of cancer are also linked to processed foods. In one study, researchers tracked the eating habits and health records of 104,980 adults for five years. The results showed that individuals who ate the most ultra-processed foods were most likely to end up with some form of cancer. The study examined the cancer risk based on the average number of servings of ultra-process foods per day and discovered that for each 10% increase in consumption, there was a 12% increase in overall cancer risk.

There’s also a high incidence of colorectal cancer among those who consume processed food. This is thought to be related to processed meats, such as lunch meat, bacon, sausage, hot dogs, beef jerky, or any other meat product that has been chemically treated to be preserved. There is some concern that red meat, like beef or pork, could cause colorectal cancer too. Studies show that eating as few as 50 grams of these products daily raises the risk by 18%. This is equivalent to a small hot dog or two slices of bacon. According to the WHO’s International Agency for Research on Cancer, processed meat, like bacon and hot dogs, can be classified as carcinogens because of the number of nitrates they contain.

Anxiety and depression are tied to diets high in processed foods. One theory behind this is that exposure to added sugars harms your gut, which is where most serotonin production occurs. Serotonin is one of your body’s mood stabilizers. So, if you have less than average, you’re more likely to have anxiety and depression. Since added sugars are highly addictive, your body continually craves more, causing the process to repeat over and over.

Worst Processed Foods

One of the worst processed foods to eat is bacon because it has high sodium, saturated fat, and preservatives. Sodium can lead to high blood pressure, while saturated fat is linked to heart disease and obesity. The American Heart Association (AHA) recommends that adults limit themselves to 1,500 to 2,300 mg of sodium a day. Just one piece of bacon can account for 8 – 13%.

Popcorn is a favorite for many people, and as long as you go easy on the salt and butter, it’s a healthy option. The problem with microwave popcorn comes from the bag. Perfluoroalkyl is just one class of chemicals found in it, which has been linked to numerous health problems. Another issue is the number of servings in most standard popcorn bags—usually, it’s upwards of three. Most people eat far more than a single serving. Microwave popcorn is often made with controversial palm oil. The AHA recommends that no more than 5 – 6% of your daily calories come from saturated fat. For a healthier alternative, buy corn kernels and pop them on your stove.

Right up there with popcorn as far as being a staple for most people is ketchup. A small amount is fine, but the volumes and frequency we put it onto food is problematic. The tomatoes in ketchup are so diluted by sugar and salt that they offer no nutritional value. Make a healthier option yourself by using a cup of tomato paste with a teaspoon of vinegar and flavoring it to taste with sugar or salt.

Margarine was once believed to be a healthy alternative to butter. The truth is that it has a lot of trans fats, which is unhealthier than any other fat, including saturated fats. If you want to have a good substitute with the smooth consistency of margarine, try mashed avocado. If you’re cooking or baking, try using nut milk or yogurts.

When it comes to quick and easy meals, frozen dinners are the next best thing to takeout. The problem is that classic frozen dinners are packed with sugars, fat, and sodium. If you plan on buying frozen meals, find ones that are organic or low sodium with an ingredient list containing foods you recognize. Another option is to create your own. You can do this by cooking a meal and freezing it in small portions that can be warmed quickly. While it may take some extra planning ahead of time, it’ll be ready to go when you need it.

An additional quick choice that is a go-to for many people is instant ramen. The challenge with this is that it has high sodium and fat amounts while being a simple carbohydrate, meaning it offers almost zero nutritional support. Before you add the flavor packet (which has 100mg of sodium by itself), a packet of ramen can contain 14g of fat and over 1,500mg of sodium. It also has other additives, like monosodium glutamate (MSG). Instead, try zucchini noodles. In fact, these can be used in place of virtually any traditional pasta.

When you’re hungry, you might think of reaching for some nuts because they contain healthy fats. Just make sure not to reach for flavored nuts because they’re loaded with extra salt and sugar. Also, the sticky flavoring makes them the enemy of healthy teeth. Instead, choose unflavored nuts and eat them plain, or roast/toast them.

One food that is often considered healthy but surprisingly isn’t…granola bars. These snacks are full of added sugars and don’t offer much in the way of good nutrition. If you want to have a granola bar, you should try making your own because you can control the amount of sugar in them or use stevia to sweeten them.

Another food that many believe to be healthy is dried fruits, like raisins. Since they have a good amount of fiber, vitamins, and minerals, they’re a better option than candy. However, even a tiny portion has many calories due to their high sugar content. Also, avoid candied fruit. These products are dried fruit that has added sugar or syrup. A healthier alternative is frozen fruit. A plus is that it’s often cut into bite-sized chunks.

Many people also like fruit snacks. The issue is that most varieties contain only a small portion of actual fruit ingredients while having large quantities of high fructose corn syrup and cane sugar. Between the excess sugar and gelatinous ingredients, the snacks are great at sticking to teeth, providing an ideal environment for bacteria to grow, resulting in cavities.

What Can You Do

The most important thing you can do when selecting food is to be aware of specific ingredients. When scanning the ingredients listed on the package, remember that they’re listed in order of quantity by weight (the item that weighs the most will be listed first), and some ingredients (ex. sugar and salt) may be listed by other names. This can include corn syrup, high-fructose corn syrup, honey, agave nectar, cane sugar, evaporated cane juice, coconut sugar, dextrose, malt syrup, molasses, or turbinado sugar.

The recently updated Nutrition Facts label requires manufacturers to list how many added sugars are in a product. Additional labels for sodium include monosodium glutamate or disodium phosphate. Another good rule of thumb is to try to avoid any chemicals that you can’t pronounce. A helpful thing to know is that processed foods dominate the center aisles of a typical grocery store. So, do your best to shop the perimeter of the store.

Whenever given the option, choose whole, unprocessed, or minimally processed foods. This doesn’t mean you suddenly have to shift everything to this but start by swapping out a few items and going from there. Gradually do more food prep and cooking at home. Moderation and common sense are key. Fatty, sugary, or salty processed foods shouldn’t account for more than 20% of your daily food intake. When selecting processed foods, look for those labeled no salt added, low-sodium, or reduced-sodium.

Ultra-processed foods not only taste good but are often inexpensive. However, when you consider all of the health problems they’re related to, it’s easy to see why you should choose less processed, whole foods. Start by making small changes. Soon you’ll notice the difference in how you feel, and it’ll help you stay healthy in the long run.