Anthropometry and the prevalence of child obesity in China and Japan

Abstract

Despite the huge socioeconomic differences between China and Japan, the rapid increase of child obesity in both countries is alarming. The prevalence of overweight and obesity in children has increased two to four fold in the two countries over the past three decades. In the 2002 China National Nutrition and Health Survey (2002 CNHS), the prevalence of overweight and obesity in children and adolescents was 3-4 times to that 30 years ago. In children aged 0-6 years, 3.4% of the children were overweight and 2.1% were obese, according to WHO recommended weight-for-height Z -score (WHZ) criteria (overweight: 2< WHZ ≤ 3,obesity: WHZ >3). For Chinese children and adolescents aged 7-17 years, the prevalence of overweight and obesity in 2002 CNHS were 4.5% and 2.1%, respectively, analyzed by using body mass index (BMI) cut-offs for Chinese children and adolescents (made by the Chinese Obesity Work Group, COWG). Using the same criterion, prevalence of overweight and obese students aged 7-22 years in 2005 were 8.72% and 5.01%, respectively, in urban areas, and were 4.61% and 2.63% in rural areas. Urban children have a higher risk of being overweight and obese than rural children. Prevalence of overweight and obese children in Japanese is estimated by using the Percentage Overweight or Percentage of Standard Weight for Height (POW). The prevalence of overweight and obesity in boys and girls increased from 6.1% to 7.1%, respectively, in the time-period from 1976 to 1980, to 11.1% and 10.2% in 1996 to 2000 estimated by using the 85th percentile BMI cut-off values. Overall, boys have a higher prevalence of being overweight and obese, and the increasing trend was most evident in 9-11 year old children in both countries. Weight-for-height Z -scores and BMI cut-offs for Chinese children and adolescents are frequently used for child overweight and obesity screening in China. POW is usually used for child overweight and obesity screening in Japan. In this chapter, we present obesity related anthropometrical indices in population and the cut-offs for child overweight and obesity in the two countries.