The goal of this clinical trial is to learn about the effect of urolithin A, a dietary supplement, on blood flow in middle-aged adults with obesity. The main question it aims to answer is: \- Does urolithin A supplementation improve blood flow in large and small blood vessels in middle-aged adults with obesity? Participants will be asked to: * Take the dietary supplement daily for 4 weeks * Attend two study visits to have their blood vessels checked, answer questionnaires, and give a sample of blood Researchers will compare people who took the dietary supplement with others who took a placebo to see if the blood flow in the blood vessels improved.