by (AP FILE)
By-JoNel is a national reporter covering food and nutrition.
Whether they know it or not, most Americans don’t go a day – or often a single meal – without eating ultra-processed foods.
From sugary cereals at breakfast to frozen pizza at dinner, as well as snacks between potato chips, sodas and ice cream, up to about 60% of the US diet is ultra-processed foods. For children and teenagers, it is even higher – about two-thirds of what they eat.
That’s a concern because ultra-processed foods have been linked to many negative health effects, from obesity and diabetes to heart disease, depression, dementia and more. One recent study suggested that eating these foods may increase the risk of early death.
However, the science of nutrition is tricky, and most research to date has found links to the health effects of these foods.
Food manufacturers argue that processing improves food safety and supplies and provides a cheap, convenient 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 account for 73% of the US food supply, according to one study.
The Associated Press asked several nutrition experts and here’s what they said:
What are ultra-processed foods?
Most foods are processed, whether by freezing, grinding, fermentation, pasteurization or other methods. In 2009, Brazilian epidemiologist Carlos Monteiro and colleagues first proposed that system which classifies foods according to the amount of processing they undergo, not according to nutrient content.
At the top of the four-tier scale are foods created through industrial processes and with ingredients like additives, colors and preservatives that you couldn’t replicate in a home kitchen, said Kevin Hall, a researcher who focuses on metabolism and diet at the. National Institutes of Health.
Such foods often make them cheap and irresistible, said Dr. Neena Prasad, director of Bloomberg Philanthropies’ Food Policy Program.
“They have the right combination of sugar, salt and fat and you can’t stop eating them,” said Prasad
However, it’s not just the level of processing that determines whether a food is unhealthy, Hall noted. Wholegrain bread, yoghurt, tofu and infant formula are highly processed, for example, but they are also nutritious.
Are ultra-processed foods harmful?
This is the tricky part. Many studies suggest that diets high in such foods are linked to negative health outcomes. But these types of studies can’t say whether the foods are causing the negative effects – or whether there’s something else about the people who eat these foods that might be responsible.
At the same time, ultra-processed foods, as a group, tend to have higher amounts of sodium, saturated fat and sugar, and are lower in fiber and protein. It is not clear whether it is only these nutrients that are driving the effects.
Hall and his colleagues were the first to conduct a small but influential experiment that directly compared the results of eating similar diets made of ultra-processed foods versus unprocessed foods.
Published in 2019the research included 20 adults who went to live at an NIH center for a month. They were given diets of ultra-processed and unprocessed foods that were matched for calories, sugar, fat, fiber and macronutrients for two weeks each and were told to eat as much as they liked.
When the diet participants ate ultra-processed foods, they ate about 500 more calories per day than when they ate unprocessed foods, the researchers found—and gained about 2 pounds (1 kilograms) on average during the study period. When they ate only unprocessed foods for the same amount of time, they lost about 2 pounds (1 kilogram).
Hall is now conducting a more detailed study, but the process is slow and expensive and results are not expected until the end of next year. He and others argue that such definitive research is needed to determine exactly how ultra-processed foods affect consumption.
“It’s better to understand the mechanisms that drive the adverse health effects, if they’re driving them,” 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 prompt government and industry to change policies. She calls for actions such as increased taxes on sugary drinks, stricter sodium restrictions for manufacturers and restrictions on the marketing of such foods to children, in the same way that tobacco marketing is restricted.
“Do we want to put our children at risk of getting sick while we wait for this perfect evidence to emerge?” said Prasad. Earlier this year, FDA Commissioner Robert Califf addressed the topic, telling a conference of food policy experts that ultra-processed foods are “one of the most complicated things I’ve ever dealt with.”
But, he concluded, “We have to have the scientific basis and then we have to continue.”
How should consumers manage ultra-processed foods at home?
In countries like the U.S., it’s hard to avoid highly processed foods — and it’s unclear which ones to target, said Aviva Musicus, science director for the Center for Science in the Public Interest, which recommends food policies. .
“The range of ultra-processed foods is so wide,” she said.
Instead, it is better to be careful about the ingredients in foods. Check the labels and align options with the Current US Dietary Guidelinesshe suggested.
“We have very good evidence that added sugar is not great for us. We have evidence that high sodium foods are not great for us,” she said. “We have great evidence that minimally processed fruit and vegetables are very good for us.”
It is important not to vilify certain foods, she said. Many consumers do not have the time or money to cook most meals from scratch.
“I think foods should be joyful and delicious and not involve moral judgment,” Musicus said.
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The Associated Press Health and Science Section is supported by the Howard Hughes Medical Institute Science and Media Education Group. The AP is solely responsible for all matters.
