The experiment involved having participants follow two diets: one containing highly processed foods and another containing minimally processed foods. Regardless of calorie count, highly processed foods consistently led participants to eat more and gain more weight.
“Though we examined a small group, results from this tightly controlled experiment showed a clear and consistent difference between the two diets,” said researcher Dr. Kevin D. Hall. “This is the first study to demonstrate causality -- that ultra-processed foods cause people to eat too many calories and gain weight.”
What’s in our food
To see how highly processed foods affected consumers’ eating habits and weights, the researchers had 20 participants -- 10 males and 10 females -- experiment with two different diets for two weeks at a time for one month.
The highly processed diet included foods that contain high fructose corn syrup, artificial flavorings, and hydrogenated oils, among other ingredients. The diet containing minimally processed foods offered healthier options and gave participants more fruits, vegetables, and proteins. However, both diets were the same nutritionally; regardless of what their meals consisted of, the participants were consuming the same amount of calories, carbs, fiber, sugar, and fat.
By the end of the month, the nutritional information was the only thing that remained the same between the participants, as following the highly processed diet led to some concerning health results.
The researchers found that participants on the highly processed diet were not only eating faster at mealtimes, they were also consuming around 500 more calories per day than their counterparts; participants following this diet gained about two pounds at the end of the two weeks.
Conversely, those who followed the minimally processed food diet lost about two pounds at the end of their two weeks, which the researchers credit to the protein they were given at meals.
The researchers were primarily concerned with how these results can affect consumers’ health in the future, and they hope this information is helpful when mealtime rolls around.
“Over time, extra calories add up, and that extra weight can lead to serious health conditions,” said Dr. Griffin P. Rodgers. “Research like this is an important part of understanding the role of nutrition in health and may also help people identify foods that are both nutritious and accessible -- helping people stay healthy for the long term.”
Plenty of risks
A number of recent studies have explored the health risks that come with consuming processed foods that many consumers may not be aware of. Researchers have found that a popular food additive found in processed foods and meats can actually influence the effectiveness of the flu vaccine.
“If you get a vaccine, but part of the immune system doesn’t learn to recognize and fight off virus-infected cells, then this can cause the vaccine to be less effective,” said researcher Robert Freeborn.
Moreover, researchers have found that highly processed foods can increase consumers’ risk of cancer, and even in small amounts can lead to an early death.