India will overtake China to become the world's most populated country in just eight years, according to a United Nations report.Meanwhile, the Chinese population will decrease by 31.4 million between 2019 and 2050. The report titled ''The World Population Prospects 2019: Highlights'' estimated that the world's population is expected to increase by two million by 2050, from 7.7 billion today to 9.7 billion.