December 20, 2023 – Figuring out why ultra-processed foods (UPFs) are linked to more chronic health conditions like heart disease and obesity stays a vital mystery for nutrition experts. If that is the case, the worst offenders could possibly be taxed or regulated by the federal government, while other UPFs that profit people could possibly be reformulated to make them less of a long-term health threat.
In the meantime, Americans can select healthier options, enjoy riskier foods carefully and take note that UPFs are sometimes high at social gatherings. Also take note that some foods are difficult – like whole grain bread from the supermarket, cauliflower crust pizza, and a few breakfast cereals which will sound healthier but are literally highly processed foods.
“The other thing that always surprises me is ketchup,” said Josiemer Mattei, PhD, MPH, Donald and Sue Pritzker Associate Professor of Nutrition on the Harvard TH Chan School of Public Health in Boston. Yes, ketchup accommodates tomatoes, “but it’s actually a processed food.”
Almost everyone has their guilty pleasure or comfort food, including Mattei and the opposite experts who recently spoke during a webinar sponsored by the TH Chan School. Mattei, for instance, said she doesn't want to provide up processed coffee creamer.
Kevin Hall, PhD, senior researcher on the National Institute of Diabetes and Digestive and Kidney Diseases, brings ready-made, microwaveable meals to work because they're convenient. Although the dietary profile of many meals includes whole grains, vegetables, and legumes, most of those are classified as highly processed foods. “I still eat these foods every day at work and choose the ones that I think are probably not that bad for me.”
UPFs are ubiquitous
It's probably unrealistic to ask everyone to provide up their favorite UPFs. One reason, “surprising or not, is that highly processed foods now account for nearly 60% of the calories in the American diet, which is concerning,” said webinar host Larissa Zimberoff, freelance journalist and writer of Technically Food: Insights into Silicon Valley's Mission to Change the Way We Eat.
Experts say it's not only excess calories, salt, sugar or other ingredients in UPFs that result in poorer health over time. For example, research from the NIH shows that folks offered a weight loss plan high in UPFs eat about 500 calories more per day than people offered a weight loss plan without UPFs, but again, nobody is bound why.
Clearly something else is happening.
“What is it about a diet rich in highly processed foods that causes people to consume excess calories, gain weight, gain body fat and, presumably over long periods of time, potentially develop obesity and a range of downstream metabolic consequences? Hall asked. “We still don’t know the mechanism… but we have a whole bunch of ideas about what the mechanism might look like.”
A mystery packed right into a microwaveable burrito
A number one theory is that UPFs are simply higher density foods. Another theory is that UPFs could also be higher in “nutrient pairs” resembling sugar and fat, salt and fat, or salt and carbohydrates.
“At least in some other studies, these couples appear to potentially increase motivation to consume excess calories,” Hall said.
“We need a lot more information,” agreed Jerry Mande, MPH, CEO of the nonprofit Nourish Science and associate professor of nutrition on the TH Chan School. “We should know exactly what ultra-processed foods are all about…so that we as consumers can make better choices.”
So while researchers seek for the UPFs that cause probably the most harm, the overall consensus is: It's the whole amount of UPFs in an individual's weight loss plan that makes the difference. There is evidence that “higher consumption and intake of UPFs overall is associated with a higher risk of developing diabetes,” Mattei said. New evidence also suggests the next risk of heart disease. Research can also be fairly consistent that artificially and sugar-sweetened beverages and animal products, especially processed meats, can increase the chance of diabetes and heart disease.
Tackling food inequality
Addressing food inequality is an important aspect of minimizing the risks of UPFs, said Mande, who has worked on the FDA and USDA throughout his profession. Food as medicine and other initiatives “must be distributed fairly. We have populations that may not have access or may be targeted to consume UPFs at higher levels due to marketing.”
The issue of food equity is vital, as is developing programs that respect cultural differences and help address structural and economic barriers to healthy eating.
“Unless you're in a really privileged position in this environment, where, again, almost 60% of the food is highly processed foods, it's extraordinarily difficult to avoid highly processed foods,” Hall said. “I don’t know anyone… with a back garden and a personal chef who can prepare all of these foods from scratch every day.”
“For the rest of us,” he continued, “we need to use what we already know to select what we believe are probably the healthiest versions of the delicious, convenient and affordable foods we can incorporate into our everyday lives.”
The goal will not be to “throw the baby out with the bathwater,” Hall said. Many UPFs are popular because they're tasty, inexpensive, and don't require lots of time or equipment to organize.
“A lot of families rely on them to kind of make ends meet and make their families happy at the end of the day,” he said. “So we need to know which foods can be redesigned in the future to make them healthier for us.”