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This just in: Junk food is not good for your health.
We jest, but recent research reveals just how damaging ultra-processed foods can be.
Research shows that 60% of Americans’ daily caloric intake typically comes from ultra-processed foods, which often contain high levels of sodium, refined sugars, cholesterol-spiking fats and other lab-based ingredients.
What’s more, a recent study linked exposure to these foods to 32 poor health outcomes, such as a higher risk of cardiovascular disease, cancer, metabolic syndrome, obesity, non-alcoholic fatty liver disease, Type 2 diabetes and premature death.
In yet another new study, it gets worse.
Researchers at the Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center in Munich and the University of Tubingen in Germany found that those adverse effects might be dangerously easy to acquire, and long-lasting, too.
Researchers found that even in the short-term, consuming a high-calorie diet rich in ultra-processed foods impairs brain insulin responsiveness and increases liver fat in healthy men.
These effects linger long after the eating period, according to the researchers.
Insulin regulates appetite and metabolism, and insulin resistance such as the kind triggered by ultra-processed foods compromises this regulation and contributes to obesity, Type 2 diabetes and cognitive dysfunction.
The German team also found a link between ultra-processed food consumption and disruption in the brain’s reward learning response. This suggests that as little as five days of overeating can condition the brain for unhealthy eating patterns.
As part of the study, 29 healthy male participants between 19 and 27 were divided into a high-caloric diet (HCD) group and a control group.
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Over five days, the HCD group was asked to eat additional daily calories from ultra-processed snack foods. The control group, meanwhile, maintained their regular diet.
The aim of the study was to assess insulin-induced brain activity during three moments: Before the high-caloric diet, during it and one week after subjects returned to eating normally.
The HCD group increased their daily caloric intake by 1,200 calories on average, and liver fat content in that group increased dramatically, while brain insulin responsiveness also increased.
One week after resuming a regular diet, insulin activity was significantly lower in the brain.
Researchers were surprised at the effect short-term HCD had on reward learning, which is the process by which the brain learns to associate behaviours or stimuli with a positive or negative outcome and modify accordingly.
After five days of eating ultra-processed foods, the HCD group showed decreased reward sensitivity and increased punishment sensitivity.
After a week of normal eating, this trend let up but didn’t fully reverse itself.
“Data suggest that a short-term HCD, rich in sugar and saturated fat, has prolonged effects on the brain that outlast the time frame of its consumption,” according to the research team.
“Habitual daily intake of sweet and fatty snacks has been shown to increase neural responses to food, while decreasing the preference for low-fat food independent of changes in body weight and metabolism.”
The study is gender specific and more research is required, but the team said, “the brain response to insulin adapts to short-term changes in diet before weight gain and may facilitate the development of obesity and associated diseases.