People who eat ultra-processed foods consume 500 more calories daily than when they eat minimally processed foods, according to a study by the US National Institutes of Health and published in Cell Metabolism.
< img src="https://medportal.ru/pictures/news/563ed587-486c-469c-b8e8-9f3694c42d6f/medium.jpg" />
This is the first randomized controlled trial investigating the effects of ultra-processed foods (packaged or instant, containing added sugars, refined carbohydrates, industrial fats, sodium and synthetic flavors and preservatives).
Previous observational studies of large groups of people have shown an association between diets high in processed foods and health problems. However, the information received could not answer the question whether processed foods were the culprits, or whether the people who consumed them had health problems for other reasons.
“Although we studied a small group, the results of this highly controlled experiment showed a clear and consistent difference between the two diets. This is the first study to show a causal relationship: ultra-processed foods cause people to eat too many calories and gain weight,” said Kevin Hall, lead author of the study.
The experiment involved 20 healthy adult volunteers (10 men and 10 women, the average age of which was 31 years). For four weeks, they lived in the research center, where for two weeks (in random order) they ate only ultra-processed foods or, conversely, minimally processed. Both sets of meals contained equivalent amounts of calories, sugar, fiber, fat, and carbohydrates. Participants could eat as much as they wanted.
The processed food diet contained no obvious unhealthy foods. The foods suggested by the researchers are consumed daily by many and are considered nutritious — breakfast cereals, muffins, white bread, sweet yogurt, low-fat potato chips, canned food, processed meats, fruit juices and diet drinks.
The second diet was based on the consumption of foods with minimal processing — fresh fruits and vegetables, eggs, legumes, fried chicken, fish and beef, as well as whole grains, nuts and seeds.
The most striking finding was that when By eating the ultra-processed food, the participants received an additional 500 calories per day, mostly from carbohydrates and fats. This resulted in an average weight gain of two pounds (about 1 kg) in two weeks.
The researchers found that when eating unprocessed foods, the appetite suppressant hormone levels increased, while the levels of ghrelin (which stimulates hunger) decreased.
“We need to find out exactly which aspects of ultra-processed foods influenced eating behavior people and led them to weight gain. The next step is to develop similar studies revisiting the ultra-processed diet to see if these changes can affect calorie intake and body weight,” Kevin Hall shared his plans.
Researchers believe that some differences in levels protein between ultra-processed and unprocessed diets could potentially explain up to half the difference in calorie intake.
Despite the health benefits of minimally processed foods, the researchers also note: “We must remember that less processed foods take longer to cook and more money. Simply telling people to eat healthier may not be effective for some people without better access to healthy food.”