The pop star tweeted, "join A BODY REVOLUTION" with a link to the photo on her site. The photo itself had the caption, "Bulimia and anorexia since I was 15."
Lady Gaga admitted she gained around 25 pounds recently in a radio interview before her European tour. However, the admission was lighthearted at the time; she blamed the weight gain on her father's Italian cooking.
Dozens of fans have since left comments on the website of encouragement and stories of similar battles against eating disorders.