Mapping the Global Obesity Challenge: Adult Data from the IMPACT-O Study

Dr Sourabh Sharma and Dr Sanjay Kalra

“The IMPACT-O study revealed that despite the high prevalence of overweight and obesity across seven countries, only a small fraction of affected individuals had a formal diagnosis or recorded BMI in their health databases.”

Obesity affects almost one in four adults in developed countries. In 2022, the World Health Organization estimated that about 2.5 billion adults worldwide had a body mass index (BMI) of 25 kg/m² or above, with nearly 890 million of them classified as obese.

The prevalence of obesity has tripled since 1975 and continues to rise, especially among people from lower socio-economic groups. It is closely linked to serious health problems such as cardiovascular disease, type 2 diabetes, and certain types of cancer. Although lifestyle changes, medications, and bariatric surgery can help manage obesity, it is still not consistently treated as a chronic disease within many healthcare systems.

The IMPACT-O study analyzed electronic medical records and insurance data from seven countries—France, Germany, Italy, Spain, the United Kingdom, Australia, and Japan—to understand how obesity is recorded and how often obesity-related complications (ORCs) occur. BMI was recorded for only 4.8–38.9% of adults and 3.5–24.9% were identified as overweight or obese. Formal diagnosis rates were low, ranging from 2.9% in France to 50.1% in Germany. Most adults (59.6–85.0%) had at least one ORC, commonly hypertension, dyslipidemia, depression, or type 2 diabetes.

The study showed that despite the high prevalence of obesity, few individuals have a recorded diagnosis, and many BMI values are missing. It shows that most adults with obesity have multiple related complications, and more than half of those with overweight also have at least one.

The findings emphasize the need for consistent documentation, broader measures beyond BMI to assess risk, and stronger public health strategies to improve recognition and management of obesity.

(Source: Artime E, Spaepen E, Zimner-Rapuch S, et al. Epidemiology landscape and impact of overweight and obesity in adults: multi-country results from the IMPACT-O study. Adv Ther. 2025;42:5148–5163. doi:10.1007/s12325-025-03333-1.)

*Dr Sourabh Sharma, Associate Professor, Department of Nephrology and Renal Transplantation, VMMC and Safdarjung Hospital, New Delhi; and Dr Sanjay Kalra, Treasurer, International Society of Endocrinology (ISE), Vice President, South Asian Obesity Forum ((SOF), Bharti Hospital, Karnal, India