The word "thin" may be derogatory, so we can choose a more euphemistic way to address thin people. Here are some possible options:

1. Thin people: This word emphasizes thinness, but it does not mean contempt or belittle.

2.Slim: This word is usually used to describe people who are slender and well-proportioned, and it is also a more neutral name for people who are thin.

3. Thin: This word is usually used to describe a thin figure, but it has a certain positive meaning, indicating that the other party is full of energy and vitality.

4. Thin: This word is used to describe thin, but it does not mean contempt or belittle, and it is an objective description.

No matter what kind of address we choose, we should take respect and goodwill as the premise and avoid using words that may cause misunderstanding or offense.