In the Netherlands, about half of all adults are currently living with overweight. This number is expected to rise to as much as 64% by the year 2050, especially among younger adults aged 18 to 44. Overweight and obesity increase the risk of chronic conditions such as heart disease, diabetes, and joint problems. However, there is no single cause behind these issues. Instead, they result from a complex combination of factors - including nutrition, physical activity, sleep, stress, income, environment, and even air quality. These factors often influence each other and vary from person to person.

This study aims to better understand these patterns and connections. By analyzing large sets of data, researchers are identifying different subtypes of people with overweight or obesity. These subtypes reflect groups of individuals who share similar personal, lifestyle, and environmental characteristics. Understanding these differences makes it possible to develop more personalized lifestyle advice and support. That way, care and prevention efforts can be better tailored to what people actually need and what works best for them in practice. Experts from various fields are helping interpret the results, so that scientific insights can be translated into practical solutions for individuals, communities, and healthcare settings.

Overweight and obesity are increasingly prevalent in the Netherlands. Obesity-related health issues are complex and influenced by multiple interacting variables, including personal behaviors, socioeconomic status, environmental characteristics, and health conditions. This study seeks to validate and enrich the results of an ongoing exploratory data analysis by involving experts in the interpretation of identified factor clusters related to BMI categories.

This mixed methods study includes a quantitative component (an online survey) and a qualitative component (expert panel group discussions). Experts are recruited through purposive and snowball sampling and participate in interpreting variable clusters, assessing associations, and drawing conclusions on implications for further research and practical application.

Inclusion Criteria:

• researchers or professionals with expertise in obesity, lifestyle, environment, psychosocial or medical factors;
• experience in data interpretation and/or public health;
• able to communicate in Dutch;
• willing to participate in the online survey and/or expert panel meeting

Exclusion Criteria:

• no relevant domain expertise;
• inability to give informed consent

The study population consists of expert researchers and professionals from diverse domains including obesity research, medical and psychosocial health, lifestyle behavior, and environmental health sciences. Participants are selected using purposive sampling within the professional networks of the research team, followed by snowball sampling to include additional relevant experts. All participants have demonstrable expertise in interpreting data related to BMI or related influencing factors, and are capable of contributing to the interpretation of complex variable clusters from an interdisciplinary perspective.