The International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) is a federation composed of national associations of bariatric surgeons. Currently, 38 nations are officially members of IFSO. There are also individual members from countries that thus far have not formed a national association.

IFSO is divided into 4 regional chapters:

1. European including Middle East and Africa
2. North America
3. Latin America
4. Asia Pacific