Consumption of ultra-processed foods has increased over the past two decades across nearly all segments of the US population, according to a new study by researchers at NYU School of Global Public Health.

“The overall composition of the average US diet has shifted towards a more processed diet. This is concerning, as eating more ultra-processed foods is associated with poor diet quality and higher risk of several chronic diseases,” said Filippa Juul, an assistant professor and postdoctoral fellow at NYU School of Public Health and the study’s lead author.

“The high and increasing consumption of ultra-processed foods in the 21st century may be a key driver of the obesity epidemic.”

In the new study, published in the American Journal of Clinical Nutrition, Juul and her colleagues analysed dietary data from nearly 41,000 adults who took part in the CDC’s National Health and Nutrition Examination Survey from 2001 through 2018. Participants were asked what they ate in the past 24 hours, and the researchers sorted the foods reported into four categories:

• Minimally processed foods (whole foods), such as vegetables, fruits, grains, meat, and dairy
• Processed culinary ingredients, such as olive oil, butter, sugar, and salt
• Processed foods, such as cheese, canned fish, and canned beans
• Ultra-processed foods, such as frozen pizza, soda, fast food, sweets, salty snacks, canned soup, and most breakfast cereals

The researchers then calculated the percentage of calories consumed from each food group.

Ultra-processed food consumption grew from 53.5 percent of calories in the beginning of the period studied (2001-2002) to 57 percent at the end (2017-2018). The intake of ready-to-eat or heat meals, like frozen dinners, increased the most, while the intake of some sugary foods and drinks declined. In contrast, the consumption of whole foods decreased from 32.7 percent to 27.4 percent of calories, mostly due to people eating less meat and dairy.

People across nearly all demographic groups, regardless of income, increased their consumption of ultra-processed foods, with the exception of Hispanic adults, who ate significantly less ultra-processed foods and more whole foods compared with non-Hispanic white and Black adults.

College graduates also ate significantly less ultra-processed foods. Notably, older adults (aged 60+) experienced the sharpest increase in consuming ultra-processed foods: this age group ate the least ultra-processed foods and most whole foods at the beginning of the period studied, yet ate the most ultra-processed foods and least whole foods at the end.

As a result of the findings, the researchers recommend implementing policies to reduce the consumption of ultra-processed food, such as revised dietary guidelines, marketing restrictions, package labelling changes, and taxes on soda and other ultra-processed foods. They also support programs and policies to increase the availability, accessibility, and affordability of whole foods, especially among disadvantaged populations.

“In the current industrial food environment, most of the foods that are marketed to us are in fact industrial formulations that are far removed from whole foods. Nevertheless, nutritional science tends to focus on the nutrient content of foods and has historically ignored the health implications of industrial food processing,” added Juul.