Obesity is a multifactorial chronic disease that results from a complex interplay between genetic, metabolic, socio-economic, behavioral and environmental factors that override the physiological mechanisms involved in body weight regulation. Importantly, obesity acts as a gateway to many other non-communicable diseases such as type 2 diabetes, cardiovascular disease and several types of cancer. According to current estimates, nearly 1 billion people around the world were living with obesity in 2020. That is about 1 in 7 people! Therefore, obesity and its associated health problems also have a significant economic impact on our health care system.

A common misconception is that obesity is always the result of an unhealthy lifestyle, that it is the result of a lack of discipline, that it is a person’s own fault. The stigma that society attaches to obesity has a significant impact on the lives of people with obesity. Talking about obesity, explaining the complexity of this disease, may help reducing obesity stigma.

What is your view on the importance of World Obesity Day as researcher?

World Obesity Day is a global campaign, which serves to raise awareness, promote advocacy, enhance policies and facilitate the sharing of experiences in the field of obesity. It is a unified day of action that calls for a cohesive, cross-sector response to the current obesity crisis. Also, as obesity scientists we are calling on everybody to work together to improve our understanding of obesity, and make progress with respect to the prevention and treatment of this chronic disease. This also means that we should challenge misconceptions that halt progress, and influence policy to better embed obesity prevention and management in our food, infrastructure and healthcare systems.

What are important areas for future obesity research and management, and what challenges do you face as a researcher?

It has become increasingly clear that obesity is not a homogeneous entity but a very heterogeneous disease. Since the causes of obesity, weight cycling and related complications can differ between individuals, not all people living with obesity will benefit to the same extent from lifestyle and/or pharmacological approaches. A better understanding of the mechanisms underlying inter-individual differences in obesity-related cardiometabolic complications is needed to develop more personalized prevention and treatment strategies to achieve more pronounced improvements in health and wellbeing.

Phenotyping beyond BMI is needed

Despite the wide recognition of obesity as a multifactorial chronic disease, the clinical recommendations guiding the diagnosis of obesity and its management, however, have not been aligned sufficiently with the clinical processes adopted for other chronic diseases. In many settings, the diagnosis of obesity is still solely based on Body Mass Index (BMI) cut-offs, not reflecting the role of adipose tissue distribution and function in the severity of the disease. Therefore, phenotyping beyond BMI is needed to accurately assess the health status of an individual. Since abdominal obesity is associated with an increased risk of developing chronic cardiometabolic diseases, measurement of the waist circumference provides important additional information about the health status of an individual. Moreover, the indications for using the different therapeutic approaches currently available for obesity management remain mostly based on anthropometric measurements, rather than on a more complete clinical evaluation of the patient (medical, functional and psychological impairments). This is in sharp contrast with the management of other chronic diseases.

Future challenges

An important step forward in the management of obesity is that we will move beyond BMI. Together with my colleagues from the European Association for the Study of Obesity (EASO), we are working hard to develop a new framework for the diagnosis, staging and management of obesity in adults, which is more aligned with the concept of obesity as an adiposity-based chronic disease. This framework may aid scientific advancements and the development of new clinical practice guidelines, thus improving obesity management in adults living with obesity.

As a researcher, it can be challenging to acquire the resources needed to perform important studies in the field of obesity. In my opinion, much more funding should be made available to study this important complex chronic disease. For sure, better obesity prevention and treatment will significantly reduce the prevalence of many obesity-related diseases, thereby reducing the global burden of non-communicable diseases.

How do NUTRIM researchers contribute to this theme?

The translational research we perform within NUTRIM focuses on the entire life cycle of people to improve preventive lifestyle strategies as well as treatment approaches. Scientists within NUTRIM have access to state-of-the-art research facilities for metabolic phenotyping, unique patient cohorts and biobanks, allowing mechanistic studies to investigate the etiology of chronic diseases. For example, we try to better understand the mechanisms underlying cardiometabolic complications in people with obesity, which may contribute to more personalized lifestyle and/or pharmacological interventions to improve cardiometabolic health and quality of life. Furthermore, we investigate why some people are inactive and eat unhealthy food, and explore how we can influence these choices (making healthy choices easier), thus reducing the public health impact of chronic metabolic diseases.

Gijs Goossens, NUTRIM Professor of Cardiometabolic Physiology of Obesity