Bariatrics is the name of the branch of medicine that studies and treats obesity. Doctors in this field may use food plans, medicine, or surgery. A physician, Raymond E. Dietz, coined the word in 1961. It is built like pediatrics or geriatrics: the -ics means “the field,” not a simple plural. Ordinary people almost never say “I work in bariatrics”; they say they see a weight-loss doctor, or they talk about 減重. You will find the noun in textbooks and on some hospital doors. Though actually, the adjective bariatric is the form you will meet more often, especially in bariatric surgery.

減重醫學、肥胖醫學（科名）。台灣門診更常寫「減重代謝」；大陸較常說減肥。