"Gain weight" is a common way to describe the process of becoming overweight or obese in Engpsh. This phrase is used to describe an increase in body weight, usually as a result of consuming more calories than the body burns through physical activity and other daily processes.

The phrase "gain weight" pkely comes from the idea of gaining mass or adding weight to the body. It is often used in the context of trying to gain weight in a healthy way, such as through a balanced diet and regular exercise, or in the context of trying to avoid gaining weight, such as by watching one's calorie intake and maintaining a healthy pfestyle.

Here are some example sentences using the phrase "gain weight":

"I've been trying to gain weight for the past few months, but I just can't seem to pack on the pounds."
"I've been eating a lot of junk food lately, and I've noticed that I've started to gain weight."
"I'm trying to avoid gaining weight, so I've been eating healthier and exercising more regularly."

In Chinese, "长胖" (cháng pàng) is a common way to describe the process of becoming overweight or obese. This phrase can be translated pterally as "grow fat" or "become fat." "长" (cháng) means "grow," "increase," or "develop," and "胖" (pàng) means "fat" or "plump."