Fat children grow up to be fat adults [1]. Such an association has been demonstrated throughout the world, from Tehran [2] to Tokyo [3] and from France [4] to Finland [5]. This is also true in China, the most populous country in the world. China has joined the world epidemic of obesity [1,6]. Not only are adults getting obese in China, children in China are also getting fatter [1,7–11] (Figs. 1 and 2). Fat children (Fig. 3) grow up to be fat adults (Fig. 4). Urban Chinese overweight children also have higher waist circumference [12]. In urban areas in China, the prevalence of childhood obesity increased from 1.5% in 1989 to 12.6% in 1997 and prevalence of overweight increased from 14.6% to 28.9% in the same period [13]. In a more recent study reported from China, the prevalence of overweight for children was 27.7% in boys and 14.1% in girls [12]. By the end of 2000, the obesity rate of male students in Beijing, China reached 15%, doubling that of 1990 and approaching that of developed countries, as was indicated by the National Physique Survey in 2000, jointly launched by the State Sports General Administration, Ministry of Education, People's Republic of China and nine other ministries and commissions [14]. The actual prevalence would actually be higher, because the Chinese have a lower body mass index (BMI) cut-off values for both overweight and obesity [15–18]. BMI of 24 and 28 are the cut-off values for overweight and obesity, respectively, for both males and females aged 18 [19]. The recently proposed cut-off values would minimize the gaps of the BMI curve between the Chinese and the international reference. Therefore it was proposed by the Working Group on Obesity in China (WGOC) to use it as