(AP FILE)
By-JoNel is a national reporter who focuses on nutrition.
Whether they know it or not, most Americans can’t go a day—or often a single meal—without eating ultra-processed foods.
From sugary breakfast cereals to frozen pizza for dinner, plus snacks like chips, soda and ice cream, ultra-processed foods make up about 60 percent of the American diet. For children and teens, the number is even higher, accounting for about two-thirds of what they eat.
That’s concerning because ultra-processed foods have been linked to a host of negative health effects, from obesity and diabetes to heart disease, depression, dementia and more. A recent study suggested that eating these foods may increase your risk of premature death.
However, nutritional science is tricky and most research to date has found associations, but not evidence, regarding the health effects of these foods.
Food manufacturers claim that processing improves food safety and supply and is a cheap and easy way to provide a varied and nutritious diet.
Even if the science were clear, it’s hard to know what practical advice to give when ultra-processed foods make up a whopping 73% of the U.S. food supply, according to one study.
The Associated Press asked several nutritionists and here’s what they said:
What are ultra-processed foods?
Most foods are processed, whether by freezing, grinding, fermenting, pasteurizing, or other means. In 2009, Brazilian epidemiologist Carlos Monteiro and colleagues first proposed a system which classifies foods based on the degree of processing they undergo, not on their nutritional value.
At the top of the four-tier scale are foods created through industrial processes and with ingredients such as additives, dyes and preservatives that you can’t replicate in a regular kitchen, said Kevin Hall, a researcher at the National Institutes of Health who focuses on metabolism and nutrition.
According to Dr. Neena Prasad, director of Bloomberg Philanthropies’ Food Policy Program, such foods are often made cheap and irresistibly delicious.
“They have just the right combination of sugar, salt and fat and you just can’t put them down,” Prasad said.
However, the level of processing alone does not determine whether a food is unhealthy or not, Hall noted. Whole-wheat bread, yogurt, tofu and infant formula, for example, are all highly processed, but they are also nutritious.
Are ultra-processed foods harmful?
Here’s the tricky part. Many studies suggest that diets high in these foods are linked to negative health outcomes. But these studies can’t tell whether the foods themselves are causing the negative effects — or whether there’s something else about the people eating these foods that could be responsible.
At the same time, ultra-processed foods as a group tend to be higher in sodium, saturated fat, and sugar, and tend to be lower in fiber and protein. It’s not clear whether these nutrients alone are causing the effects.
Hall and his colleagues were the first to conduct a small but influential experiment in which they directly compared the results of a similar diet of highly processed and unprocessed foods.
Published in 2019The study involved 20 adults who lived at an NIH center for a month. They were each given a two-week diet of ultra-processed and unprocessed foods, matched for calories, sugar, fat, fiber, and macronutrients, and told they could eat as much as they wanted.
When participants ate the ultra-processed foods diet, they consumed about 500 more calories per day than when they ate whole foods, researchers found — and they gained about 2 pounds (1 kilogram) on average during the study period. When they ate only whole foods for the same period, they lost about 2 pounds (1 kilogram).
Hall is now conducting a more detailed study, but the process is slow and expensive, and results aren’t expected until late next year. He and others say such definitive research is needed to determine exactly how ultra-processed foods affect consumption.
“It is better to understand the mechanisms by which they cause the adverse health effects, if they do,” he said.
Should ultra-processed foods be regulated?
Some advocates, like Prasad, argue that the large body of research linking ultra-processed foods to poor health should be more than enough to spur government and industry to change their policies. She calls for actions such as higher taxes on sugary drinks, stricter sodium limits for manufacturers, and stricter measures against marketing such foods to children, in the same way that tobacco marketing is curbed.
“Do we want to risk our children getting sicker while we wait for this perfect evidence to emerge?” Prasad said. Earlier this year, FDA Commissioner Robert Califf raised the issue, telling a conference of food policy experts that ultra-processed foods are “one of the most complex things I’ve ever dealt with.”
But, he concluded, “we need to have the scientific basis and then we need to move forward.”
How should consumers handle ultra-processed foods at home?
In countries like the U.S., it’s hard to avoid highly processed foods, and it’s unclear which foods to avoid, says Aviva Musicus, scientific director of the Center for Science in the Public Interest, which advocates for food policy.
“The range of ultra-processed foods is just so broad,” she said.
Instead, it’s better to be aware of the ingredients in foods. Check labels and make choices that reflect the current US dietary guidelinesshe suggested.
“We have really good evidence that added sugar is not good for us. We have evidence that foods high in sodium are not good for us,” she said. “We have great evidence that fruits and vegetables that are minimally processed are really good for us.”
It’s important not to vilify certain foods, she added. Many consumers don’t have the time or money to cook most meals from scratch.
“I believe that food should be joyful and tasty and not dependent on moral judgments,” says Musicus.
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The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group. The AP is solely responsible for all content.