A short-term, high-caloric diet has prolonged effects on brain insulin action in men.

Summary

In healthy-weight men, brief overeating with calorie-dense sweet and fatty foods induced liver fat accumulation and impaired brain insulin action, with disruptions persisting beyond the overeating period. These findings suggest that brain insulin responsiveness adapts rapidly to dietary excess before weight gain, potentially priming pathways toward obesity and metabolic disease.

Key Findings

• Short-term overeating with calorie-rich sweet and fatty foods induced liver fat accumulation in healthy-weight men.
• Brain insulin action was disrupted and the impairment outlasted the overeating period.
• Brain insulin responsiveness can adapt to short-term diet changes before weight gain, potentially facilitating obesity development.

Clinical Implications

Counseling should emphasize that even brief high-calorie overeating may durably impair brain insulin action and increase liver fat, supporting earlier lifestyle interventions and monitoring in at-risk individuals.

Limitations

• Sample size and male-only population limit generalizability.
• Short-term follow-up without long-term clinical outcomes; non-randomized design.

Future Directions

Test reversibility and mitigation strategies (e.g., exercise, diet composition), include women and diverse populations, and elucidate neural mechanisms and exposure thresholds.