Bariatric is a doctor’s adjective for the care of people who live with obesity — body weight so high that it starts to harm health. You will see it in bariatric surgery (operations that make the stomach smaller, or change how food is taken in), bariatric clinic, and bariatric patient. It is hospital English: letters, news about operations, insurance forms. It is not a kind word to hang on someone in the street; that would sound cold. Though actually, many families never say bariatric at all. They say weight-loss surgery — and in Taiwan, 減重手術. The medical word is the precise one; the everyday words are the ones people actually speak.