Processed Foods and Junk Foods

Why Processed Foods and Junk Foods are Harmful to Your Health

November 10, 2021

If you’re like the majority of Americans, you probably consume at least some processed foods and junk foods every day. Yet most experts agree, a healthy diet should be rich in whole, natural foods and low in processed foods. But what are processed foods, and why are they bad for health? Read on to find out.

Processed Foods and Junk Foods

What Are Processed Foods?

For starters, it’s helpful to know what exactly processed food is.

Unprocessed food is the unadulterated edible portion of a plant or animal – food in its purest form.
Processed food, therefore, is any food that is altered from its most natural state.

Processed foods can be classified according to the NOVA classification system into four groups.

Processed Foods and Junk Foods

This group consists of non-processed and minimally processed foods, which are natural foods that are simply physically altered, such as by cutting, drying, grinding, or filtering, as well as by cooking via simple methods like roasting or boiling. An example of minimally processed foods would be chopped or frozen vegetables or dried fruits without preservatives added.

Processed Foods and Junk Foods

Processed culinary ingredients are those food ingredients that are derived from unprocessed natural foods via methods such as pressing, grinding, or milling, such as oils from nuts and sugar from sugar cane or sugar beets.

This group is known as processed foods, which are foods from group one which have group two ingredients added to them, and which also may be preserved through methods such as canning, smoking, or salting.

This group is known as “ultra-processed” foods, takes it a few steps further by introducing chemical additives to foods, such as preservatives and artificial colors, and by manipulating and altering foods by advanced manufacturing processes intended to increase shelf life and enhance palatability. This may include sodas and other sugary beverages, cured meats like luncheon meats or sausage, many packaged snack foods, crackers, cookies, bottled dressings and sauces, breakfast cereals, and frozen desserts treats. Each step of this process has the potential to strip foods of some of their natural goodness while adding unhealthful components. The more processed a food is, the more unhealthful it may be.

Adverse Health Effects of Consuming Excess Processed Foods

High consumption of processed foods has been linked with myriad adverse health effects, including high blood pressure and heart disease, overweight and obesity, metabolic syndrome, Alzheimer’s, and cancer.

One research review found that each 10% increase in intake of ultra-processed foods resulted in a 12% increase rate of cardiovascular disease, a 13% increase rate of coronary heart disease, and an 11% increase in cerebrovascular disease. Similarly, another review found that a 10% increase in consumption of ultra-processed foods results in a 10% increase in overall rates of cancer.

Processed meats are just one of many processed foods that are linked to chronic disease. Processed meats are those which have been preserved through methods like smoking, salting, or the addition of chemical preservatives. This includes bacon, sausage, and hot dogs, to name a few.

Several studies have linked consumption of processed meat with increased risk of cancer, and particularly the stomach, colon, and rectal cancer, such that the World Health Organization has classified processed meats as a known carcinogen based on a review of over 800 studies. The experts who conducted this review concluded that consuming 50g of processed meat daily increased the risk of cancer by 18%. That’s the equivalent of about 1 hot dog, 4-6 slices of bacon, or about 2 slices of ham.

Sodas and other sugar-sweetened beverages have also been specifically linked to poorer health. More and more research is accumulating demonstrating the many ill effects that frequent consumption of these drinks can have on health, from tooth decay to overweight and obesity, to type 2 diabetes.

What Makes Processed Foods So Bad?

Processed foods have their advantages. In fact, the purpose of various methods of food processing is to make foods more convenient, more shelf-stable, or to improve their texture and appearance. Many processed foods have vitamins and minerals added to them for our benefit, such as bread, breakfast cereals, orange juice, and milk.

The problem with highly processed foods is that often they are high in calories, added sugars, salt, and trans fats – all things which, in excess, promote inflammation and disease, and which we should be trying to reduce in our diets. This also serves to make these foods much tastier, and arguably more addictive, which can lead to overconsumption and weight gain.

As obesity is a risk factor for a multitude of chronic diseases, it stands to reason that this may be a contributing mechanism in regard to processed food’s role in disease progression.

Furthermore, eating more processed foods generally results in eating fewer nutritious, natural foods such as whole fruits and vegetables, nuts, seeds, and legumes, etc.

Consequently, we miss out on all of the wonderful nutrients they provide, such as fiber and antioxidants, and all the health benefits those nutrients impart, such as improved digestion, stable energy levels, and protection from disease.

Lastly, processed foods often contain added chemicals such as preservatives, colors, thickening agents, and emulsifiers, as well as by-products of advanced high-heat processing methods. Advanced-glycation end products (or AGEs) and acrylamide are a couple of examples of such compounds that are implicated in the development of chronic inflammation and disease.

Think about some of the ways you could reduce your processed foods consumption, and increase your consumption of natural, healthful foods. Consider some healthy swaps; for instance, use fresh-cut vegetables to dip into guacamole instead of chips, snack on nuts instead of flavored snack crackers, or choose fresh vegetables as pizza toppings instead of sausage or pepperoni.

When buying packaged foods, scan the ingredients label. As often as possible, opt for products without added sugars, salt, or preservatives, and with fewer ingredients overall. Be mindful that the term “natural” is unregulated and may not necessarily indicate that a food is unprocessed or healthful. It’s best to stick to fresh foods whenever possible.


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Processed Foods and Junk Foods
Sarah Kennedy


Sarah Kennedy RD, LD is a Clinical Dietitian with Memorial Hermann Memorial City Medical Center. She has experience serving patients with a variety of conditions in the hospital setting, as well as WLS candidates in the outpatient setting. She has a passion for food and nutrition and enjoys helping others achieve balance in their diets while attaining their wellness goals.
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