How Processed Foods Impact Your Health and Wellbeing

Eating processed foods regularly can negatively affect your health in many ways. This comprehensive guide examines the effects of processed foods on nutrition, chronic disease risk, digestive health, and more. It also provides tips for avoiding processed items and choosing healthier whole food alternatives.

What are Processed Foods?

Before diving into the health effects, let's clarify what qualifies as a processed food. The NOVA food classification system categorizes foods into four groups based on the extent and purpose of industrial food processing (1):

• Unprocessed or minimally processed foods: Edible parts of plants (seeds, fruits, leaves, etc) and animals (muscle, offal, eggs, milk) with no or minimal processing. Examples include fresh fruits, vegetables, grains, nuts, meats, fish, milk, yogurt.
• Processed culinary ingredients: Substances obtained directly from group 1 foods or nature through processes like pressing, refining, grinding, milling and filtering. These are used to prepare, season and cook group 1 foods. Examples include oils, butter, sugar, salt, vinegar.
• Processed foods: Formulated by adding salt, oil, sugar or other substances from group 2 to group 1 foods. Examples include canned fruits in syrup, salted nuts, cured meats, cheeses.
• Ultra-processed foods: Formulated entirely or mostly from industrial ingredients and additives. Examples include sodas, chips, frozen meals, chicken nuggets, candies, store-bought baked goods.

This article will focus on the health impacts of foods in the last two categories, which I'll refer to collectively as “processed foods.”

Processed Foods Lead to Poor Nutrition

A diet high in processed foods can lead to poor nutrition in several ways:

Nutrient Loss

Processing techniques like refinement, heating, and preservation deplete vitamins, minerals, and other nutrients in whole foods (2, 3). For example:

• Fiber: The fiber content of whole grains drops significantly when milled into refined flour. This affects gut health.
• Vitamins: Processes like heating and canning reduce vitamin C, B vitamins, and other heat-sensitive nutrients.
• Minerals: Milling whole grains into refined flour decreases minerals like iron and zinc.

Added Sugar, Salt and Unhealthy Fats

To improve flavor and prolong shelf life, processed foods often contain added sugar, salt, and unhealthy fats like trans fat and low quality oils (4). This promotes overconsumption and reduces diet quality.

• Sugar: The average American consumes 22 teaspoons of added sugar daily, mostly from processed foods. This increases risk of obesity, diabetes, and heart disease (5).
• Salt: 75% of sodium in the average American diet comes from processed and restaurant foods. Excess sodium raises blood pressure.
• Unhealthy fats: Numerous processed foods contain inexpensive oils high in omega-6 and trans fats that promote inflammation.

Artificial Additives

Processed foods are loaded with artificial flavors, colors, emulsifiers and other additives with questionable health effects (6). Studies link them to allergies, digestive issues, headaches and metabolic changes.

It's best to avoid artificial additives and stick to whole foods whenever possible.

Higher Calorie Density

Ounce for ounce, processed foods contain more calories than fresh foods and are easier to overconsume (7). For example, 170 calories in cookies or chips is a much smaller portion than 170 calories of vegetables and fruits. This promotes overeating and obesity.

Increased Risk of Chronic Diseases

A diet high in processed meats, refined carbs, and unhealthy fats raises the risk of various chronic diseases.

Heart Disease

Several studies associate processed food consumption with increased heart disease risk (8, 9):

• Eating ultra-processed foods for 2 weeks caused significant increases in blood pressure and LDL cholesterol compared to unprocessed meals.
• Each 10% increase in ultra-processed food intake was linked with a 12% higher risk of cardiovascular disease.

Processed foods contribute to heart disease via added sugars, sodium, unhealthy fats, and nutrient depletion.

Diabetes and Obesity

A high intake of processed foods reliably predicts future obesity and diabetes (10, 11). Possible reasons include:

• Blood sugar spikes from refined carbs and added sugars.
• Appetite stimulation from low fiber and high calorie density.
• Adverse effects of food additives on metabolism and gut bacteria.
• Overconsumption of calories.

Cancer

Certain processed meat products like bacon, salami, and hot dogs contain carcinogenic compounds that may raise cancer risk (12).

Additionally, the low fiber and high calorie density of processed foods promotes obesity, which increases cancer risk.

According to the World Cancer Research Fund, avoiding processed meats and limiting other processed foods may lower cancer risk (13).

Negative Effects on Digestive Health

The additives, sugar content, and nutrient imbalance of processed foods wreak havoc on digestive health in various ways.

Altered Gut Bacteria

The trillions of bacteria in your gut (collectively called the gut microbiota) play crucial roles in immunity, metabolism, and digestion (14).

Studies reveal that frequently eating processed foods causes major changes to gut bacteria (15):

• Reduced bacterial diversity.
• Decreased beneficial bacteria like Bifidobacteria.
• Higher amounts of inflammatory species.

This dysbiosis is linked with numerous health issues, including autoimmune disease, insulin resistance, and obesity (16).

Digestive Problems

Processed foods are linked to increased risks of inflammatory bowel disease, irritable bowel syndrome (IBS) and other digestive issues (17, 18).

Potential reasons include gut bacteria imbalance, food additives, and low fiber intake.

Impaired Nutrient Absorption

The nutrient deficiencies and gut bacteria changes caused by processed foods can impair the absorption of minerals like iron, calcium and magnesium (19).

This may contribute to anemia and poor bone health.

Tips for Avoiding Processed Foods

Here are some tips to cut processed foods from your diet:

• Shop the perimeter of the grocery store where the whole foods like produce and meat are located.
• Read ingredient lists and avoid products with sugar and unhealthy fats in the first few ingredients.
• Cook at home as often as possible rather than eating out. Restaurants serve highly processed foods.
• Choose plain whole milk yogurt and add your own fruit instead of buying flavored yogurt.
• Drink water instead of soda, fruit juice, sports drinks, and other sugary beverages.
• Buy nuts, seeds, and grains from the bulk bins instead of the processed packaged versions.
• Limit microwave meals, breakfast cereals, granola bars, crackers, and other convenience foods.

Healthy Replacements for Common Processed Foods

Instead of processed foods, choose unprocessed whole food alternatives:

• Replace fruit yogurt, pudding, or gelatin cups with plain Greek yogurt plus fresh fruit.
• Choose mashed avocado on toast over margarine or cream cheese.
• Instead of deli meats with nitrates/nitrites, try roasted chicken, turkey, or beef.
• Trade iceberg lettuce salads with creamy dressing for greens with olive oil and balsamic vinaigrette.
• Swap canned soups for homemade bone broth or pureed vegetable soup.
• Replace sugary breakfast cereal with steel-cut oatmeal topped with nuts and fruit.
• Trade crackers, chips, and pretzels for unsalted nuts, roasted chickpeas, or fresh vegetable crudites.
• Instead of boxed mac and cheese, make your own with whole grain pasta, cheese, milk, and a dash of mustard.

The Bottom Line

While the occasional processed treat is fine, making these foods a regular part of your diet can have detrimental effects on health over the long term. Nutrient loss, artificial additives, excess sugar and salt, and gut bacteria changes caused by processed foods are tied to increased risk for numerous chronic diseases.

Whenever possible, choose fresh, whole food alternatives. Emphasize plenty of fruits, vegetables, whole grains, healthy fats, herbs, spices, and other unprocessed items to get the most nutrition and minimize disease risk. With some simple substitutions, you can easily avoid processed foods and optimize your wellbeing.

References:

1. Monteiro CA, Cannon G, Moubarac JC, et al. The UN Decade of Nutrition, the NOVA food classification and the trouble with ultra-processing. Public Health Nutrition. 2018;21(1):5-17.

2. Fardet A. New hypotheses for the health-protective mechanisms of whole-grain cereals: what is beyond fibre?. Nutrition Research Reviews. 2010;23(1):65-134.

3. Rickman JC, Barrett DM, Bruhn CM. Nutritional comparison of fresh, frozen and canned fruits and vegetables. Part 1. Vitamins C and B and phenolic compounds. Journal of the Science of Food and Agriculture. 2007;87(6):930-944.

4. Moodie R, Stuckler D, Monteiro C, et al. Profits and pandemics: prevention of harmful effects of tobacco, alcohol, and ultra-processed food and drink industries. The Lancet. 2013 Feb 23;381(9867):670-9.

5. Johnson RK, Appel LJ, Brands M, et al. Dietary sugars intake and cardiovascular health: a scientific statement from the American Heart Association. Circulation. 2009 Sep 15;120(11):1011-20.

6. Carocho M, Morales P, Ferreira IC. Sweeteners as food additives in the XXI century: A review of what is known, and what is to come. Food and Chemical Toxicology. 2017 Sep 1;107:302-17.

7. Hall KD, Ayuketah A, Brychta R, et al. Ultra-processed diets cause excess calorie intake and weight gain: an inpatient randomized controlled trial of ad libitum food intake. Cell metabolism. 2019 Jul 2;30(1):67-77.

8. Srour B, Fezeu LK, Kesse-Guyot E, et al. Ultraprocessed food intake and risk of cardiovascular disease: prospective cohort study (NutriNet-Santé). BMJ. 2019 May 29;365.

9. Pagliai G, Dinu M, Madarena MP, et al. Consumption of ultra-processed foods and health status: a systematic review and meta-analysis. British Journal of Nutrition. 2021 Mar;125(5):588-601.

10. Poti JM, Braga B, Qin B. Ultra-processed Food Intake and Obesity: What Really Matters for Health-Processing or Nutrient Content?. Current obesity reports. 2017 Dec 1;6(4):420-31.

11. Krebs-Smith SM, Guenther PM, Subar AF, et al. Americans do not meet federal dietary recommendations. The Journal of nutrition. 2010 Oct 1;140(10):1832-8.

12. Carr PR, Walter V, Brenner H, Hoffmeister M. Meat subtypes and their association with colorectal cancer: Systematic review and meta-analysis. International journal of cancer. 2016 Nov 15;139(10):2295-308.

13. World Cancer Research Fund/American Institute for Cancer Research. Continuous Update Project Report: Diet, Nutrition, Physical Activity and Cancer. 2018. Available at https://www.wcrf.org/wp-content/uploads/2021/02/Summary-of-Third-Expert-Report-2018.pdf

14. Valdes AM, Walter J, Segal E, Spector TD. Role of the gut microbiota in nutrition and health. Bmj. 2018 Jun 13;361.

15. Johnson AJ, Vangay P, Al-Ghalith GA, et al. Daily sampling reveals personalized diet-microbiome associations in humans. Cell host & microbe. 2019 Apr 10;25(6):789-802.

16. Soldavini J, Kaunitz JD, Lampe JW. Is gnotobiotics the way forward for microbiome research?. Gut microbes. 2019 Jul 4;10(4):462-6.

17. Shivappa N, Bonaccio M, Hebert JR, Di Castelnuovo A, Costanzo S, Ruggiero E, Pounis G, Cerletti C, Donati MB, de Lorgeril M, Barbaresko J. Association of proinflammatory diet with low-grade inflammation: results from the Moli-sani study. Nutrition. 2018 Oct;54:182-188.

18. Vandeputte D, Falony G, Vieira-Silva S, et al. Stool consistency is strongly associated with gut microbiota richness and composition, enterotypes and bacterial growth rates. Gut. 2015 Jan 1;65(1):57-62.

19. Glahn RP, Wortley GM, South PK, Miller DD. Inhibition of iron uptake by phytic acid, tannic acid, and ZnCl2: studies using an in vitro digestion/Caco-2 cell model. Journal of Agricultural and Food Chemistry. 2002 Mar 13;50(8):390-5.

Frequently Asked Questions About Processed Foods

What are the main differences between whole and processed foods?

Whole foods are unaltered ingredients from plants or animals, like fruits, vegetables, grains, nuts, eggs, milk, and meat. Processed foods are formulated by adding salt, sugar, oil, and artificial additives to whole food ingredients. This changes their nutritional profile.

Why exactly are processed foods considered unhealthy?

Processing depletes vitamins, minerals, and fiber naturally found in whole foods. Processed items also tend to be high in added sugar, unhealthy fats, and sodium. Frequent consumption is linked to increased risk of chronic diseases like heart disease, diabetes, and cancer.

Are all processed foods equally bad?

Not necessarily. Minimally processed foods like plain yogurt, roasted nuts, and cured meats aren’t as detrimental to health when eaten in moderation. However, ultra-processed foods with many artificial ingredients like frozen meals, chips, and baked goods should be limited.

What are some examples of highly processed foods I should avoid?

Soda, sweetened breakfast cereals, flavored yogurt, margarine, frozen pizza and microwaveable meals, fast food, store-bought baked goods, candy, chips, fruit snacks, and hot dogs and deli meats with nitrates are examples of ultra-processed foods to limit.

Will cutting out processed foods help me lose weight?

Probably. Processed foods are higher in calories ounce-for-ounce than whole foods. Their refined carbs, added sugars, and unhealthy fats also stimulate overeating. Replacing processed foods with whole foods naturally leads to a calorie deficit.

How quickly would my health improve if I cut out processed foods?

You may notice benefits like improved energy, better digestion, and weight loss within weeks. However, reducing disease risk factors like inflammation, high blood pressure, and insulin resistance can take longer. Sticking with whole foods long-term is ideal.

Is it realistic to completely avoid all processed foods in today’s world?

It’s best to aim for mostly whole foods, but the occasional processed treat won't sabotage your efforts. Focus on preparing more meals at home using whole food ingredients instead of relying on packaged and restaurant items to minimize consumption.

Which nutrients are most commonly depleted in processed foods?

Processed grains and flours are lower in fiber and minerals like iron, zinc, and magnesium versus whole grains. Manufacturing also depletes B vitamins like folate, vitamin C, and other antioxidants originally found in whole fruits and vegetables.

How do processed foods harm the balance of gut bacteria?

The fiber, sugar content, nutrient profile, and artificial additives in processed foods influence the bacterial makeup of your digestive system. This can increase inflammation, impair metabolism and immunity, and cause problems like weight gain and IBS.

What are some easy meal ideas without processed foods?

Some options are oatmeal with fruit and nuts for breakfast, salad with chickpeas for lunch, and turkey chili or vegetable soup for dinner. Snack on fruit, yogurt, roasted nuts, hard boiled eggs, and raw veggies with hummus instead of packaged bars and chips.

Let me know if you need any clarification or have additional questions!