A 2023 study using genetic data from nearly 10,000 people suggests that caffeine levels in your blood may influence body fat and risk of type 2 diabetes. Researchers from the Karolinska Institute, University of Bristol, and Imperial College London found that individuals with genetic variations causing slower caffeine breakdown had lower BMI and body fat mass. The team used Mendelian randomization to establish causal links.
Approximately half of caffeine's effect on diabetes risk was mediated through BMI reduction. The study did not find a significant association with cardiovascular diseases. The researchers suggest that non-caloric caffeinated beverages could be explored for reducing obesity and diabetes risk, though more controlled trials are needed.