TUESDAY, Aug. 10, 2021 (HealthDay News) -- Frozen burgers, pizza pockets and toaster strudel. Energy drinks and sugary sodas. Fruit leather and potato chips. Cookies and cereal bars. Fish sticks and chicken strips.
These sorts of quick-pick manufactured foods are considered "ultraprocessed," and dietitians believe they could be at the root of America's obesity epidemic.
A new study has found that two-thirds of the calories consumed by U.S. children and teens come from ultraprocessed foods, an eating pattern that could be driving children toward obesity.
About 67% of calories eaten by kids and teens come from ultraprocessed foods, compared with about 61% two decades ago, according to data gathered by a top federal health survey.
At the same time, total energy consumed from unprocessed or minimally processed foods decreased from about 29% to 24%, the researchers reported.
Convenience today could be contributing to an unhealthier life for children, said senior researcher Dr. Fang Fang Zhang, an associate professor with the Tufts University School of Nutrition Science and Policy, in Boston.
"We are all busy in this modern society. We have less time to cook everything from scratch. But we seem to be relying too much on ultraprocessed foods," Zhang said. "It's a signal for us to do something about this, given the obesity rate is still very high in U.S. children."
About one in every five children are obese, according to the U.S. Centers for Disease Control and Prevention.
Ingredients that promote obesity
The concept of "ultraprocessed" foods is relatively new, first established by Brazilian dietary experts in 2017 as part of a new classification system called NOVA, and intended to consider how food is manufactured as part of its nutritional impact on humans.
"Food processing itself may have an impact on health because processing changes the physical structure and chemical composition of foods," Zhang explained. "People who eat ultraprocessed foods tend to be fatter and they tend to consume a high amount of calories."
Ultraprocessed foods are made largely of industrial substances derived from the heavy processing of "whole" foods — examples include high-fructose corn syrup, hydrogenated vegetable oil, and soy protein isolate — along with chemicals designed to add color, flavor or shelf life to the product.
Lona Sandon, an associate professor with the University of Texas Southwestern Medical Center's department of clinical nutrition, in Dallas, explained that "ultraprocessed foods are made of ingredients you generally would not find in your kitchen. They are made of ingredients extracted from foods and are typically high in sugar, fat, salt and other additives."
For this study, Zhang and her colleagues reviewed 20 years of data from the U.S. National Health and Nutrition Examination Survey, a federal poll that regularly assesses eating patterns among Americans. The data ran from 1999 through 2018.
The investigators found that children and teens across the board were getting more calories from ultraprocessed foods, regardless of their parents' education levels or income.
This "suggests that ultraprocessed foods are pervasive in the diet of U.S. youths and supports the need to reduce consumption of ultraprocessed foods among all population subgroups," the researchers concluded.
It wasn't all bad news. For example, the targeting of sugar-sweetened beverages as a source of childhood obesity led to total daily calories from these drinks declining from about 11% to about 5% over the past two decades.
If you have to cook it, it's probably better
Unfortunately, other categories of ultraprocessed foods surged during the same period. Daily calories from ready-to-heat and ready-to-eat meals increased from 2% to 11% during the same period.
A nutrient profile showed that ultraprocessed foods contain more calories from carbohydrates (55% versus 43%) and added sugars (19% versus 3%) than foods that haven't been so heavily manufactured, the study showed.
Ultraprocessed foods also contain lower levels of fiber and less protein (11% versus 21%), the researchers found.
The findings were published Aug. 10 in the Journal of the American Medical Association.
"These types of foods tend to be less satisfying than less processed and whole foods. Therefore, people eat more. They are also highly palatable, driving people to eat more," Sandon said.
"They taste good and are convenient for both parents and kids. Kids can easily help themselves to these types of foods with little or no cooking skills," she continued.
Parents and schools need to make a concerted effort to pick foods that are either whole or, at the least, subject to much less processing, experts said. Think of meals you have to actually prepare in the kitchen, versus simply heating them up.
Moms and dads crunched for time also might think of ways to increase the nutritional value of ultraprocessed foods, said Connie Diekman, a registered dietitian in St. Louis.
"If you need to serve your kids a pizza, let's take it home and let's add some vegetables to the top of it, so now we boost the nutrition but we don't compromise the convenience," Diekman said.
Cambridge University Press has more about the NOVA food classification system.
SOURCES: Fang Fang Zhang, MD, PhD, associate professor, Tufts University School of Nutrition Science and Policy, Boston; Lona Sandon, PhD, MEd, RN, LD, associate professor, department of clinical nutrition, University of Texas Southwestern Medical Center, Dallas; Connie Diekman, RD, MEd, registered dietitian, St. Louis; Journal of the American Medical Association, Aug. 10, 2021