They think that their daughter-in-law is overweight, which is a sign of good health. Such a daughter-in-law is not easy to get sick and easy to have children. That is, it doesn't take time to give birth, and there will be enough milk to feed the child after birth. These are the benefits of a fat wife.
Today's mother-in-law doesn't think so. What kind of daughter-in-law she can marry depends on her son's eyes. Daughter-in-law seldom works in the fields now, but does some housework at home at most. And now, people don't think being overweight is a good thing. Being fat is actually bad for your health.
In today's society, slim and beautiful women are more popular. After all, women hold up half the sky and earn money to support their families. Now that medical conditions are much better, it is effortless for slim and beautiful women to have children.