Thinness in Japanese Young Women

The decline in BMI among Japanese women after World War II

“…This conclusion is derived from the extrapolated BMIs for the early 1950s and is based on linearity assumptions that both age effects and cohort effects are time-invariant, and that the age-cohort interaction effect is constant throughout the 1950s. These assumptions, however, are not in line with previous findings that the effects of age and cohort among young women are highly nonlinear and time-variable (Funatogawa et al, 2008;Sugawara et al, 2009). Funatogawa et al's (2009) results for the later years indicate merely that cohorts born in the 1920s and 1930s were the peak cohorts when they were in their 50s and 60s.…”

“…, using the SHS to analyze BMI trends among schoolchildren throughout the entire 20th century, find a steady increase among both boys and girls. In contrast, NNSbased studies of young women find a downward trend in BMI since the 1970s (Takimoto et al, 2004;Sugawara et al, 2009). Funatogawa et al (2008), drawing on NNS 1 Underweight (BMI < 18.5) is becoming a public-health concern in Japan because of associated small-for-gestational-age (SGA) deliveries, high mortality, and health conditions such as low bone-mineral density (Hozawa et al, 2008;Arimatsu et al, 2009;Harita et al, 2012).…”

“…Fourth, we employ an estimation method that allows us to address the issue of the highly nonlinear nature of the relationships between BMI, age, and cohort. Many of the existing Japanese studies use linear regression models that do not conform to the previous findings of strong nonlinearity in both child and adult BMI (Funatogawa et al, 2008;Sugawara et al, 2009;. Additionally, all of the aforementioned Japanese studies rely on BMI measures aggregated by rough age and cohort groups of five-to ten-year intervals, which prevent them from providing a precise description of the BMI trend, especially shortly after the war.…”

“…In sharp contrast to this global trend, both the obesity rate and the average body mass index, or BMI, defined as (weight in kilograms) divided by (height in meter) 2 , of Japanese men and women are significantly lower than those recorded in other high-income countries. Moreover, the average BMI of Japanese women is even lower than that of their male counterparts (Finucane et al, 2011;OECD, 2012), and the age-specific BMI of Japanese women has decreased over several decades (Takimoto et al, 2004;Funatogawa et al, 2008Funatogawa et al, , 2009Sugawara et al, 2009). We calculate that the average BMI of women 25 years of age decreased from 21.8 in 1948 to 20.4 in 2010, whereas that of men increased from 21.4 to 22.3 over the same period.…”

Visceral Fat Accumulation in Japanese High School Students and Related Atherosclerotic Risk Factors

“…According to a study by the Ministry of Health and Welfare, the per-centage of young women with a body mass index exceeding 25 kg/m 2 was only 7%, and more than 20% of Japanese young women had a body mass index less than 18.5 1) . There are many studies about adolescent obesity in western countries 2) , but it is unclear whether adolescent obesity occurs in Asian adolescents in the same manner because of the different environmental and genetic factors.…”