Obesity is a multifactorial, complex disease that is driven by genetic, biological, environmental, and behavioral factors. In this review, we explain the key contributors to obesity, limitations in current definitions, its relationship with cardiometabolic health, and recent advancements in treatment. Obesity is characterized by the presence of excess and dysfunctional adipose tissue, driven by chronic inflammation and maladaptive energy homeostasis. Although body mass index (BMI) has historically been used to diagnose obesity, BMI provides a limited evaluation of individual patients because it fails to specifically quantify adiposity, which is the primary determinant of metabolic impact in these patients. There is an ongoing and necessary shift in treating obesity with a weight-inclusive approach that aims to address obesity upstream and prevent downstream cardiometabolic health complications. This approach is being supported by various treatment options, notably glucagon-like peptide-1 receptor agonists like semaglutide and tirzepatide, that also have promising effects on cardiovascular, renal, and liver health. Advances in precision medicine, gut microbiome research, and Multi-target therapies support personalized therapeutic approach. Despite these developments, less than 25% of individuals living with obesity are receiving evidence-based treatment. There is an urgent need to improve health care delivery to patients with obesity through timely, affordable, and multimodal treatments that promote sustainable and sustained weight loss. Increasing board certification of practicing physicians through the American Board of Obesity Medicine will be critical to improving access and quality of care.