On the one hand, soaking rice in soup reduces the frequency of chewing, and in the process of chewing, certain enzymes (that is, part of digestive juice) will be secreted to digest food. Soaking rice in soup will reduce the digestion of food by this enzyme and directly digest it by the stomach, which will increase the burden on the stomach and make it difficult for things to be completely digested.
On the other hand, soaking rice in soup will increase the amount of things. If it is just rice, it may be reduced to half of the original weight after chewing, but it will still be so much after adding soup, which will increase the weight invisibly and increase the extrusion on the stomach wall. Therefore, it is generally not recommended to eat rice in soup.