Unhealthy Teen Diets Reshape the Brain and Drive Lifelong Eating Habits

The following is excerpted from an online article posted by News Medical.

Researchers have recently reviewed the existing literature to understand how an adolescent’s eating behavior affects the development of the prefrontal cortex (PFC) and hippocampus (HPC), as well as overall health.

The transition from childhood to adolescence also involves a shift from dependence on direct control mechanisms linked to food and sensory receptors to an increasing reliance on indirect control mechanisms that facilitate adjustments in one’s eating behavior.

In contrast to children whose eating behavior is primarily determined by hunger and fullness cues, adolescents’ eating behavior is significantly influenced by multiple external factors, including personal beliefs, media, food preferences, and peer pressure. The modern food environment features easy-to-access, highly palatable foods with high levels of fat, sugar, and salt, often directly marketed to adolescents. These ingredients typically increase food cravings by bypassing the normal regulatory controls.

Multiple studies have shown that compared to children, adolescents are more commonly inclined towards consuming hyper-palatable and ultra-processed foods (UPF), which are widely available in Western countries. These studies have also pointed out that adolescents are the highest consumers of high-fat, high-sugar (HFHS) foods, which cause obesity and metabolic disease. According to U.S. data, ultra-processed foods account for approximately 65% of total energy intake among adolescents, who also have the highest intake of added sugars. In the last three decades, a rapid increase in the prevalence of adolescent obesity has been recorded, with rates having quadrupled during this period.

Adolescent rats fed an HFHS diet for just a month exhibited a reduced number of fast-acting parvalbumin-positive (PV+) interneurons and perineuronal nets (PNNs) in the medial prefrontal cortex (mPFC), which disrupts neuroplasticity. Notably, adolescent rodents exposed to a Western diet for as little as one week exhibited rapid onset of anxiety-like and depression-like behaviors, a vulnerability not observed in adults.

HFHS foods were found to promote impulsivity, especially during adolescence.

Rodents fed with high-fat food demonstrated increased oxidative stress in the hippocampus, higher memory impairments, anxiety, and decreased social interaction. Similarly, rodents fed high-fructose corn syrup, a key ingredient in most soda drinks, exhibited impaired hippocampal-dependent spatial learning and memory in both male and female rats.

Taken together, the habitual feeding behaviors developed during adolescence may trigger long-lasting alterations in brain circuitry that could influence health throughout the lifespan. While much of the mechanistic evidence is derived from animal studies, human epidemiological and neuroimaging data are generally consistent with these findings; however, direct causal pathways require further investigation.

Source: News Medical
https://www.news-medical.net/news/20250624/Unhealthy-teen-diets-reshape-the-brain-and-drive-lifelong-eating-habits-study-finds.aspx