What is the origin story of the custom of weighing people in the long summer?

Chang Xia said that people's weight originated in the south, and it is said that it originated in Shu during the Three Kingdoms period. After Liu Bei's death, Zhuge Liang gave Liu Bei's son to save his blood, sent him to Jiangdong, and asked Liu Bei's stepwife, Mrs. Sun, to take care of him. This day is the long summer among the 24 solar terms.

Mrs. Sun weighed Adou in front of Zhao Zilong and took good care of her. Later, Chang Xia weighed herself once a year to see how much weight the child had gained. From then on, it spread and became the custom of calling people in the long summer. Of course, Chang Xia said the origin of human body weight, and there are other theories.