Brain Region Size and Its Link to Future Weight Gain in Youth Facing Financial Hardship

Recent research highlights how brain development related to reward processing may influence weight gain in adolescents experiencing financial adversity. Children aged 9 to 12 from the Children's Hospital Los Angeles, participating in the nationwide Adolescent Brain Cognitive Development (ABCD) Study, were examined to understand the connection between economic hardship, brain structure, and weight changes. The study utilized magnetic resonance imaging (MRI) to detect subtle differences in brain regions responsible for reward and food intake control.

Findings suggest that youth experiencing high levels of financial adversity often show smaller volumes in certain subcortical regions of the brain associated with reward processing. These structural differences appeared before significant weight gain occurred, indicating that brain changes could be a precursor rather than a consequence of increased weight.

As Dr. Shana Adise explains, the classic question of whether brain differences lead to overeating or vice versa remains open. The study observed that children with higher financial adversity had smaller reward-related brain regions, which correlated with greater increases in BMI over time. Interestingly, all participants started with healthy weights; some began to transition toward unhealthy weight ranges during the study.

The research also explores the impact of stress on weight gain, noting that psychological stress activates the body's stress response system, leading to increased cortisol levels. Elevated cortisol can promote fat storage and stimulate appetite, especially in the brain's appetite regulation centers. Overactivation of inflammatory processes in the brain due to stress and weight gain can damage neurons, potentially influencing future brain development and behavior.

Overall, this study underscores the importance of early interventions during adolescence—the critical period when the brain undergoes many changes. Addressing factors like financial stress and supporting healthy neurodevelopment may help prevent weight-related health issues later in life.

For more details, see the original study published in the Journal of Adolescent Health (2025).