Functional characterization of obesity using advanced 3D in vitro adipose tissue models

Obesity represents a complex systemic disease resulting in the global metabolic syndrome epidemic, yet our understanding of the underlying mechanisms in adipose tissue driving obesity remains limited. As the primary cellular targets of increased caloric intake, adipocytes undergo dramatic morphological and functional changes that trigger systemic metabolic dysfunction. To study the dysfunctional obese adipocyte phenotype in vitro, revolutionary three-dimensional (3D) adipocyte models have shown to be uniquely capable of recapitulating the lipid-laden, hypertrophic adipocyte characteristic of obesity. This feature makes 3D in vitro platforms powerful alternatives to traditional two-dimensional monolayer systems where the large, spherical and buoyant adipocytes simply detach. These sophisticated 3D in vitro New Approach Methodologies (NAMs) now enable researchers to dissect the multifactorial nature of obesity through diverse functional assays that validate individual disease hallmarks and assess therapeutic interventions. However, the field faces a critical challenge: integrating multiple disease-relevant readouts into holistic interpretations that can unlock novel adipocyte-targeting mechanisms. This review provides a comprehensive roadmap of cutting-edge 3D adipose tissue systems, showcasing how these NAMs can revolutionize biological and drug target discovery in obesity research. We examine the functional assays that define these models' capabilities, address key interpretative challenges, and explore transformative opportunities to amplify their impact through high-throughput approaches and scalable functional platforms that will accelerate the next generation of obesity therapies.