The purpose of this study is to test whether tadalafil causes subcutaneous adipose tissue to have a "beige" phenotype. Participants will be randomized to either placebo or tadalafil for 12 weeks. Investigators will study adipose metabolism using MRI scans and aspiration of subcutaneous adipose from the abdomen. In addition to MRI scans at room temperature, the investigators will use a cooling protocol to test the combined effects of tadalafil and on adipose metabolism. Investigators will also measure the effects of the drug on body composition. In addition to the study visits, participants will wear an activity tracker (Fitbit) and log their dietary intake several times using an online tool. There will be a small amount of radiation exposure. Participants will be compensated for participation in this study.