Junk Food Binge May Alter Brain Insulin Response

High-Caloric Diet Disrupts Brain Insulin Action and Increases Liver Fat in Healthy Men

A 5-day high-caloric diet led to liver fat accumulation and disrupted brain insulin function in healthy men, with effects lasting even after returning to a normal diet. Researchers suggest that the brain's insulin response may adjust to dietary changes before any weight gain occurs, potentially promoting obesity development.

Key Findings:

• The high-caloric diet group showed significant increases in liver fat and higher insulin activity in brain regions (right insular cortex, left rolandic operculum, right midbrain/pons).
• After returning to a regular diet, the high-caloric group had lower insulin activity in the hippocampus and fusiform gyrus, with changes linked to fat and saturated fatty acid intake.
• Participants on the high-caloric diet also exhibited reduced reward sensitivity and increased punishment sensitivity after just 5 days.

Takeaway: The study demonstrates that short-term overeating of ultra-processed, high-caloric snacks can lead to liver fat accumulation and disrupted brain insulin function, with effects lingering beyond the dietary intervention period.