Article continues below advertisementOne of the world's greatest athletes just confessed to taking a weight-loss drug.Serena Williams revealed during an interview on Thursday, August 21, that she started using a GLP-1 medication about one year ago, and as a result, has shed 31 pounds amid her ongoing health and wellness journey."I was on and off (the medication) and now completely on," she told the Today show. "It was a really good decision I had to make for my life, you know, I tried everything.