Decoding the complex systems of obesity

We present this special focus issue on March 4th, coinciding with World Obesity Day 2025, to show our solidarity with the World Obesity Federation and advocate for increased awareness, prevention, and treatment of obesity. We embrace this year's World Obesity Day theme, "Changing Systems," which challenges us to broaden our perspective from viewing obesity as solely an individual issue and recognize the wider systemic factors that contribute to the rapidly escalating rates of obesity worldwide. As researchers and as editors we often take a narrow view, focusing on specific genes, molecules, or cell signaling pathways that impact metabolism and contribute to obesity. However, with this issue, we aim to expand that view, presenting papers that highlight how body systems cooperate to impact metabolic health and, more broadly, how environmental factors, including food systems, contribute to this complex disease. By understanding the systems that influence obesity on a broader level, we can hope to optimize current disease management and to uncover novel approaches to combat it.