Young Ju, Ph.D.

Humans have been cooking and processing foods since the dawn of humanity. How does food processing affect your health? This article explores the different levels of processing along with examples as well as benefits and adverse effects of ultra-processed foods on health.

Food Processing

Food processing can be defined as essentially those techniques used to transform food from original sources into food ingredients or food products in order to make the food safe, shelf-stable, convenient to use, tasty, and/or more nutritious (1).

Food can be classified into four groups depending on the degree of processing (called the NOVA system).

Trends of Ultra-Processed Food Consumption

Due to their low cost and convenience, ultra-processed foods make up a significant part of Americans’ diet. In 2018, ultra-processed foods comprised about 60% of total calories in the US diet (3) compared to 53.5% of total calories during 2001-2002 (4). It’s estimated that more than 73% of the US food supply is ultra-processed (5)

Sales data (6) show that functional and flavored water, concentrates, dairy products and alternatives, sports and energy drinks, and certain tea and coffee sales have been steadily increasing since 2006. Many commercial sports foods (e.g., sports foods, sports drinks, meal replacement products, sports supplements) are also classified as ultra-processed foods, and these products are increasingly used as convenient aids to performance.

Ultra-Processed Food Consumption and Health

Effects of ultra-processed foods on health vary since these foods are processed very differently. Research has shown that fortified breakfast cereals and plant-based dairy alternatives could provide some health benefits by providing vitamins and minerals, such as calcium, protein, fiber, and vitamins Bs and D.

Some ultra-processed foods not only have low nutritional value, association-type research studies have also shown strong associations between higher consumption of ultra-processed foods and increased poor health outcomes and risks of many chronic diseases (including certain types of cancer, type 2 diabetes, irritable bowel syndrome, obesity, and heart disease), mortality, depression in adults, asthma/wheezing in adolescents, metabolic syndrome in adolescents, and high cholesterol in children (7-11). However, experimental studies that examined cause-effects were unable to conclude that ultra-processed food intake caused these health conditions.

Reducing Intake of Ultra-Processed Foods with Low Nutrition Value and UsIng Ultra-Processed Foods in a Healthy Diet

Many countries, including the US, have been working to establish unified and impactful policies for reducing ultra-processed food consumption, such as taxing ultra-processed foods and requiring package labeling. Eating lots of ultra-processed food also means leaving less room for healthier foods. You can reduce ultra-processed food intake (particularly, those with low nutritional value) in the following ways:  

•  Cook at home more using whole foods (e.g., fresh, frozen or canned).

•  Prepare healthy meals in larger amounts when cooking, and portion and freeze to use later, instead of buying ready-to-eat meals.

•  In general, avoid ready meals or pre-made sauces or ingredients.

•  Swap ultra-processed foods with healthier alternatives, e.g., instead of adding sugar or sweeteners, use fresh, frozen, or dried fruits or eat nuts instead of other processed snack types.

Researchers at the US Agricultural Research Service also conducted a study demonstrating that it’s possible to make a healthy diet with more than 80% of your daily total calories (2000 cal per day) from ultra-processed foods while also following the recommendations from the 2020-2025 Dietary Guidelines for Americans (12). You can find a 7-day sample menu in Reference (13)(https://www.sciencedirect.com/science/article/pii/S0022316623724346?via%3Dihub).  

Conclusions

Food processing methods range from basic freezing or milling to more complex technologies that promote stability, palatability, and diversity. Research evidence suggests that ultra-processed foods are bad for our health.  However, with restricted time and budgets, eating only minimally processed foods may not be an option. The bottom line is that you should always try to use unprocessed or minimally processed foods and freshly made meals rather than ultra-processed foods. Reading the Nutrition Facts Labels is a good place to start to make healthier food choices. Also, not all ultra-processed foods are equal. When you include ultra-processed foods in your diet, choose those that have more nutritional benefit.

People with health problems should talk to their healthcare providers. This information is provided for your reference, and you use at your own risk; you should rely on your medical professional for medical advice.

References

1. The NOVA Food Classification https://ecuphysicians.ecu.edu/wp-content/pv-uploads/sites/78/2021/07/NOVA-Classification-Reference-Sheet.pdf

2. Harvard School of Public Health. Processed Foods and Health. https://www.hsph.harvard.edu/nutritionsource/processed-foods/

3. Baraldi et al. Consumption of ultra-processed foods and associated sociodemographic factors in the USA between 2007-2012: evidence from a nationally representative cross-sectional study. BMJ Open. 2018, 8(3):e020574.

4. Juul et al. Ultra-processed food consumption among US adults from 2001 to 2018. Am J Clinical Nutr. 2022, 115(1):211.

5. Menichetti et al. Machine learning prediction of the degree of food processing. Nat. Commun. 14:2312.

6. Baker et al. Ultra-processed foods and the nutrition transition: Global, regional and national trends, food systems transformations and political economy drivers. Obesity Reviews 2020, 21:e13126.

7. Rico-Campa et al. Association between consumption of ultra-processed foods and all cause mortality: SUN prospective cohort study. BMJ 2019,365:l1949.

8. Srour et al. Ultra-processed food intake and risk of cardiovascular disease: prospective cohort study (NutriNet-Sante). BMJ 2019:365:l1451

9. Elizabeth et al. Ultra-processed foods and health outcomes: A narrative review. Nutrients 2020, 12(7):1955.

10. Lane et al. Ultra-processed food consumption and mental health: A systematic review and meta-analysis of observational studies. Nutrients 2022, 14:2568.

11. Valicente et al. Ultraprocessed foods and obesity risk: A critical review of reported mechanisms. Adv Nutr 2023, 14(4):718.

12. Dietary Guidelines for Americans. https://www.dietaryguidelines.gov/resources/2020-2025-dietary-guidelines-online-materials

13. Hess et al. Dietary Guidelines meet NOVA: Developing a menu for a healthy dietary pattern using ultra-processed foods. J Nutr. 2023, 153(8):2472. 

This information is provided for your reference and you use at your own risk; you should rely on your medical professional for medical advice.