I do not wish to add fuel to the fire by entering into a discussion on food advertising versus physical inactivity as the culprit for childhood obesity that was prompted by Dr Ashton's editorial (February 2004 JRSM1). I always tell my overweight or obese patients that body fat does not grow on the tree; it has to come from an external source, either overeating or underexertion. The best example comes from China.
China used to be known for her slender people; I never saw a fat person in China until very recently.2 Now China is fighting obesity, especially childhood obesity, just like the rest of the world. According to the latest statistics from China, the proportion of obesity among children under the age of 15 increased from 15% in 1982 to 27% today.3 Among the predisposing factors for increasing prevalence of childhood obesity in China, fast food and physical inactivity are the two most important. Because of the efficient advertisements of such fast food giants in the United States as McDonald's and Kentucky Fried Chicken, Chinese children are devouring the American fast food faster than ever.2,4 All of the children in China recognize the image of Ronald McDonald, even though they might not be able to read English.4
That physical inactivity is the other important risk factor for obesity in Chinese children is illustrated by three observations. First, the effect of television on childhood obesity in China has been documented: each hourly increment of television viewing is associated with a 1-2% increase in the prevalence of obesity in urban China.5 Second, childhood obesity is more prevalent in urban areas than in rural areas, not only because children in rural China are physically more active6 but also because urban boys consume more fat than rural boys—23-30% versus 16-20%.7 Third, urban children in China are engaged in more homework because they are under pressure to achieve scholastically, whereas rural Chinese children are engaged more in field work because of economic necessity.8
References
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