Official Japanese reports significantly underestimate prevalence of overweight in school children: Inappropriate definition of standard weight and calculation of excess weight.
BACKGROUND
The obesity epidemic in Japan continues to increase. However, the prevalence and trends of obesity have not explicitly been determined in Japanese children.


OBJECTIVE
The study estimated the trend and prevalence of overweight in Japanese school children, 1980-2001.


METHODS
The 2001 cross-sectional national survey on 334,939 boys and 335,204 girls, 5-18 years of age was studied, using the 1978-1981 references. Main outcome measures were proportion of children with BMI > or =95th centile and those with > or = + 20% excess body weight.


RESULTS
The prevalence of overweight increased 2.6 times (5.0% to 12.9%) in Japanese boys and 2.5 times (5.0% to 12.5%) in Japanese girls during the last two decades as assessed by using BMI, whereas the Japanese Ministry of Education, Culture, Sports and Science and Technology reported a much smaller increment in prevalence (5.8% to 9.2% in boys, 5.6% to 8.0% in girls, respectively) using the same data but based on a cut-off value of > or = + 20% excess body weight.


CONCLUSIONS
Official governmental reports significantly underestimate the current epidemic of obesity in Japan.
Inokuchi
Mikako
M
Department of Paediatrics, Keio University School of Medicine, Tokyo, Japan.
Matsuo
Nobutake
N
Takayama
John I
JI
Hasegawa
Tomonobu
T
D000293:Adolescent; D001837:Body Weights and Measures / Q000592:standards*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D050177:Overweight / Q000453:epidemiology*; D015995:Prevalence