[Developmental Origins of Health and Disease (DOHaD) and Epidemiology].

Japan has the highest proportion of low-birth-weight infants among OECD countries for over 20 years. In 2011, the proportion of low-birth-weight infants in Japan was 9.6%, whereas the mean proportion in OECD countries was only 6.8%. In particular, young Japanese women's strong desire to be thin has been pointed out as the underlying cause. Indeed, the frequencies of unhealthy thinness among third-year female junior and senior high school Japanese students have been increasing since the start of "Healthy Parents and Children 21", and both groups have reached about 20%. The hypothesis of the fetal origins of adult disease (Barker's theory) was proposed by Professor David J. Barker of Southampton University, who had conducted descriptive epidemiological studies in England and Wales and birth cohort studies in Hertfordshire, for example. In early 21st century, it became the wider theory known as the "Developmental Origins of Health and Disease (DOHaD)", which was composed of developmental plasticity and the mismatch concept. Birth cohort studies are believed to be suitable for epidemiological studies to demonstrate the DOHaD theory. These studies and their collaborations are very popular in European countries, whereas such collaborations lagged behind in Japan. Recently, a new paradigm, "preemptive medicine", has been proposed in Japan. The importance of interdisciplinary studies focusing on fetal and childhood periods was also recommended as a political strategy. We just expect the realization of nationwide large-scale interdisciplinary research projects based on DOHaD and preemptive medicine and the establishment of a central research institute of these studies.