Epidemiology Landscape and Impact of Overweight and Obesity in Adults: Multi-country Results from the IMPACT-O Study

Introduction: To estimate the recording rates and impact of overweight/obesity across selected countries in Europe and Asia–Pacific. Methods: IMPACT-O was a retrospective cohort study of electronic medical records and claims databases from France, Germany, Italy, Spain, the UK, Australia, and Japan. Recording levels and the number of adults with overweight/obesity [based on diagnostic codes and/or body mass index (BMI)] during 2018–2022 were estimated. BMI thresholds/categories and obesity-related complications (ORCs) were described for adults with ≥ 1 BMI record of ≥ 25.0 kg/m² and ≥ 12 months observation before the index date. Results: The number of active subjects across databases ranged from 1,203,674 to 22,413,902. BMI was recorded for 4.8–38.9% of active patients. The number of adults with overweight/obesity ranged from 3.5% in Australia to 24.9% in the UK. The percentage of individuals with BMI > 25 to < 30 kg/m² ranged from 43.6% in Spain to 77.9% in Japan; the percentage with BMI ≥ 30.0 kg/m² ranged from 22.1% in Japan to 54.8% in Spain. Among those with overweight/obesity, the percentage with diagnosis codes in their records ranged from 2.9% in France to 50.1% in Germany. Most (59.6–85.0%) individuals had ≥ 1 ORC; 35.9–65.8% had multimorbidity. The most frequently recorded ORCs were hypertension, dyslipidemia, depression, and type 2 diabetes. Conclusion: Only a small proportion of people with overweight/obesity are formally diagnosed in healthcare databases. Most present with ≥ 1 ORC, commonly hypertension, dyslipidemia, depression, and type 2 diabetes.