Recent research revealed that 60% of Americans’ daily caloric intake comes from ultra-processed foods.
UPFs often contain high levels of sodium, refined sugars, cholesterol-spiking fats and other lab-based ingredients.
A recent study linked exposure to UPFs to 32 poor health outcomes, including a higher risk of cardiovascular disease, cancer, metabolic syndrome, obesity, nonalcoholic fatty liver disease, Type 2 diabetes and even premature death.
Now, a new study suggests that many of those adverse effects might be dangerously easy to acquire and shockingly long-lasting.
Researchers at the Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen in Tübingen, Germany, found that even in the short term, consuming a high-calorie, UPF-rich diet impairs brain insulin responsiveness and increases liver fat in healthy men.
What’s more, and worse? These effects linger long after the eating period.
Insulin regulates appetite and metabolism, and insulin resistance — like the kind triggered by UPFs — 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, suggesting that as little as five days of overeating can condition the brain for unhealthy eating patterns.
For the study, 29 healthy male participants between 19 and 27 were divided into a high-caloric diet (HCD) group or a control group.
Over five days, the HCD group was told to eat additional daily calories from ultra-processed snack foods.
The control group maintained their regular diet.
The study aimed to assess insulin-induced brain activity during three moments: before the high-caloric diet, during it, and one week after subjects went back to eating normally.
On average, the HCD group increased their daily caloric intake by 1,200 calories.
Liver fat content in that group increased dramatically, while brain insulin responsiveness increased as well.
One week after resuming a regular diet, insulin activity was significantly lower in the brain.
An earlier study published in JAMA Neurology found that people could be at a higher risk of cognitive decline if more than 20% of their daily caloric intake is ultra-processed foods.
In the German study, researchers were stunned at the effect short-term HCD had on reward learning, the process by which the brain learns to associate behaviors or stimuli with a positive or negative outcome and modify accordingly. This process is pivotal to motivation, decision making and food choices.
To measure the relationship between HCD and reward learning, participants completed a task to assess their sensitivity to reward and punishment and the brain’s efficacy in processing and adapting to feedback.
After a scant five days of eating UPFs, the HCD group displayed decreased reward sensitivity and increased punishment sensitivity. After a week of normal eating, this trend abated but did not 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.”
While the study is gender specific and more research is needed, the team posits, “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.”
The Centers for Disease Control and Prevention defines obesity as having a body mass index of at least 30, and a shocking 20% of Americans meet that criteria.
Nearly 60% of US adults with obesity have high blood pressure, and approximately 23% have diabetes. People with obesity are at a higher risk for a slew of health problems, including heart and liver disease on top of a multitude of chronic conditions.
