Gender-affirming hormone therapy is the bedrock of medical therapy for many transgender and gender diverse individuals. Some adult transgender individuals decide with their health care provider to start hormone therapy – testosterone for transmasculine people and generally a combination of estrogen and antiandrogens for transfeminine people – specifically for the physical and psychological effects these hormones produce, including changes to the voice, skin, facial and body hair and body composition. However, in the context of the global obesity epidemic, little is known about obesity rates and weight changes in adults treated with gender-affirming hormone therapy.