When you open a bag of nacho-flavored chips or cheese puffs, you know you're probably about to eat an unhealthy snack.
A gift from the dead? It's a deliciously spicy, cheesy neon orange powder that coats every bite and sticks all over your fingers. The same goes for frozen pizza and chicken nuggets.
But what about granola bars? Applesauce pouch? String cheese? Flavorful yogurt? Snacks that millions of children and adults eat every day, these foods certainly can't be bad, right?
Well, it turns out that depending on the exact ingredients, many of them fall into the category of ultra-processed foods. This kind of food has been well studied recently, but the results are not very good.
Ultra-processed foods are a relatively new way of classifying foods. The system, proposed in 2009 by researchers at the University of São Paulo in Brazil, is called NOVA and is based not on the type of food, such as meat, grains or vegetables, but on how it is processed.
NOVA classifies foods into four groups. From the first category of whole foods and minimally processed foods to the fourth category of ultra-processed foods using industrial formulations and manufacturing techniques.
“My actual definition of ultra-processed[food]is that it can't be made in a home kitchen because there's no machinery or ingredients,” food policy expert Dr. Marion Nestle told CNN medical correspondent Meg. . Tyrrell recently appeared on the podcast “Chasing Life.” Nestlé is Paulette Goddard Professor Emeritus of Nutrition, Food Research, and Public Health at New York University.
Ultra-processed foods contain additives such as flavor enhancers, colorants, and thickeners, and typically use ingredients that are not normally used in cooking. They keep well, are easy to prepare (just heat and eat), and are often hard to resist. (The food industry has opposed the NOVA system, citing a lack of scientific consensus on the definition of ultra-processed products.)
A confluence of historical, regulatory, and economic factors led food companies in the 1980s to “expend great effort to figure out what flavor, texture, and color combinations were most appealing to people.'' , let them make a lot of money.”
Since then, tens of thousands of new products have hit store shelves. “Most of them fail, but the winning companies reap big profits,” Nestlé said.
Want to know more about what you're eating before you reach for that can of soda, bag of chips, or frozen dinner? Here are 5 things you should know about ultra-processed foods .
Ultra-processed foods are linked to health hazards
Eating lots of ultra-processed foods is not healthy.
“Currently, more than 1,500 observational studies have been conducted, all showing consistent findings: eating ultra-processed foods is linked to obesity, type 2 diabetes, heart disease, certain cancers, and the effects of COVID-19. “poor outcomes from viral infections, overall mortality rates,'' Nestlé said. “Possible negative health issues related to diet are particularly associated with ultra-processed foods.”
A new study published Wednesday in the BMJ journal analyzed more than 30 years' worth of data and found that eating ultra-processed foods lowers the risk of death from all causes by 4%, including a 9% increased risk of death from neurodegeneration. % was found to increase. . Other studies have linked ultra-processed foods to heart disease, type 2 diabetes, cancer, and mental health disorders such as anxiety and depression.
Nestlé pointed out that these studies were observational and not designed to prove a causal link that ultra-processed foods caused these poor health outcomes.
“You can do that by doing controlled clinical trials,” she says. “And guess what? We have one.”
Ultra-processed foods cause weight gain
One randomized controlled clinical trial showed that ultra-processed foods actually cause people to gain weight.
This type of research is not easy or cheap to conduct, so it is not done very often. To conduct the study, Dr. Kevin Hall, a senior investigator at the National Institute of Diabetes and Digestive and Kidney Diseases, had 20 volunteers spend four weeks at the National Institutes of Health Clinical Center in Bethesda, Maryland. I received it.
For two weeks, they ate a diet consisting of 80% healthy, ultra-processed foods (think yogurt and whole-wheat bread, not potato chips and soda). For the remaining two weeks, I ate a diet free of ultra-processed foods. Diets were matched, especially regarding calories, sugar, fat, fiber, and macronutrients. Participants did not know what exactly the study was measuring.
“We basically just asked people to eat as much or as little of whatever they wanted,” Hall told Tyrrell. “You shouldn't try to change your weight, nor should you try to gain or lose weight. Eat at the same appetite level as usual.”
The researchers found that when participants ate an ultra-processed diet, they ate about 500 more calories per day than when they ate a minimally processed diet. This calorie difference is immediately reflected on the scale. Participants gained an average of 2 pounds over two weeks on the ultra-processed diet and lost 2 pounds on the minimally processed diet. And blood tests showed lower markers of inflammation when taking the latter.
“If you're not familiar with nutrition research, you have no idea how important a finding this is,” said Nestlé, who was not involved in the study. “500 calories is amazing.”
Hall said it's unclear what causes people to eat more calories when consuming ultra-processed foods. “One of the things we're really interested in now is figuring out what the mechanism was,” he said.
It's hard to avoid ultra-processed foods
Ultra-processed foods are everywhere, and most of us consume them without realizing it, even when we think we're eating something relatively healthy, like baked potato chips or peanut butter and jelly sandwiches. .
Using data from the National Health and Nutrition Examination Survey, researchers found that ultra-processed foods make up more than half of the diets of American adults. For children in the United States, the rate is even higher: 67%.
Ultra-processed foods are cheap and convenient
Yes, that's right. It costs more to eat truly “clean” food.
“It actually cost about 40% more to create a minimally processed menu than a super processed menu,” Hall says. “That doesn't even take into account the time it takes to make the dish, right? So all of these factors probably play a big role in the food we choose to eat in the real world.”
Not all ultra-processed foods are bad
Some ultra-processed foods, such as whole grain bread and yogurt, can provide important nutrients. Hall's research also showed that some people do not increase their calorie intake.
“The snacks were neutral in terms of the number of calories (participants) consumed,” Hall said. “This shows that not all ultra-processed foods necessarily promote this effect.”
Hall's team is conducting new research to determine which ultra-processed foods are harmful and which are harmless or even healthy.
Americans may soon receive more help sorting out the health effects of ultra-processed foods. The U.S. Department of Agriculture and the U.S. Food and Drug Administration will soon issue new dietary guidelines that will be updated every five years. Nestlé said the scientific advisory committee guiding the process was asked to consider the link between ultra-processed foods and poor health.