An extensive UK study has revealed that a healthy lifestyle can significantly weaken the association between genetic predisposition to obesity and type 2 diabetes (T2D) risk, even for individuals who are not visibly overweight. The findings were in European Journal of Endocrinology.

Researchers from the UK Biobank cohort analyzed data from over 220,000 White British adults to assess how polygenic risk scores for body mass index (BMI-PRS) and waist-hip ratio (WHR-PRS) relate to future diabetes risk. The findings emphasized that people with both high genetic risk and visible obesity had the greatest odds of developing T2D.

For those with high BMI-PRS, the hazard ratio (HR) for developing diabetes was 3.72 compared to individuals with low genetic risk and no obesity. Similarly, those with high WHR-PRS had a 4.17-fold increased risk. However, the study highlighted that modifiable lifestyle factors, such as diet, physical activity, sleep, and smoking, meaningfully impacted these risks.

Lifestyle alone explained about 30% of the diabetes risk in people with high BMI-PRS and 20% in those with high WHR-PRS. When combined with phenotypic obesity, lifestyle accounted for over 90% and 70% of the respective risk.