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In Hong Kong, obesity in children has been defined as having a body weight 20% over the median weight of those of the same height and same gender. Since 1993, cut-off criteria has been determined using the height and weight data collected in 1993, and prevalence of childhood obesity has been reported annually using the 1993 criteria. From 1993 to 2004, childhood obesity has increased from 8.9% to 14.2% for girls, and 11.3% to 20.6% in boys. The increases exceed 70% in 11 years time. However, we also observed that the median height and weight of Hong Kong children have been increasing simultaneously in the past decade, this may due to the improvement in living quality. If so, the prevalence of childhood obesity we reported nowadays using the 1993 may be misleading due to the fact that the overall stature of Hong Kong children nowadays is different from 1993. We therefore found that there is a need to review the 1993 reference values for defining childhood obesity and to report a revised figures using the current stature status.

From year 2001-2206, the Department of Sports Science and Physical Education of the Chinese University of Hong Kong conducted several large scale citywide physical fitness surveys and collected 30,845 school student (age 6-18 years) data on body height and weight. From the data collected, we found that the prevalence of childhood obesity has increased to 16.8% for girls and 22.5% for boys. The increase is double as compared to 1993. However, when we take the median weight for the same height of the same sex from 2006 and use this as reference values for defining childhood obesity, we found that the prevalence of childhood obesity is 12.4% for girls and 15.6% for boys, the increases are still 40% higher than those reported in 1993. In conclusion, the childhood obesity in Hong Kong is increasing annually, regardless the fact that there are increases in both height and weight, the prevalence of obesity is alarming. Childhood obesity is a serious health problem and is strongly associated with a number chronic diseases such as cardiovascular diseases and metabolic diseases. Being obese also bring significant adverse impact on psychological wellbeing and school learning.

In today's press conference, Prof Stanley Hui Sai-chuen, Associate Professor of the Department of Sports Science and Physical Education at CUHK reported the above analysis of childhood obesity in Hong Kong, including the annual changes of the prevalence in childhood obesity from 1993 to 2006, and the data revised using the reference values in 2006 instead of in 1993. A seminar on childhood obesity and physical activity for primary teachers was also held today. A number of topics were explored at the seminar which include the followings: i/ Prof. Stanley Hui lectured on childhood obesity, physical activity and health as well as IT application; ii/ Mr. Raymond Sum proposed some feasible activity ideas that teachers could adopt to tackle childhood obesity; iii/ Two colleagues from the Information Technology Section of the Education and Manpower Bureau shared some initiatives in using IT to promote children physical activity; iv/ Two primary school teachers also shared their experiences in implementing weight control initiatives in their own schools; and v/ Prof. Lu Dajiang from Shanghai Sports Institute demonstrated some useful computer program for monitoring childhood obesity and prescribing exercise for obese children.