…there is no clear evidence that schools are contributing to the growth in obesity.the obesity-related complaints about school lunches, vending machines, and physical education are based largely on the assumption that these factors are causing our kids to get fat.yet, i find little evidence to support this claim.for example, in looking at survey data on the health behavior of middle and high school students, the factor i found that best predicted whether or not a kid was obese was tooth brushing .more important than how much junk food they ate, soda they drank, or physical education they received was whether or not they brushed their teeth.among fourteen- to seventeen-year-olds, only 16 percent of kids who brushed their teeth more than once a day were overweight compared to 24 percent who brushed less than once a day.of course, other factors were important as well — teenagers who play more computer games, eat more fast-food, and drink less whole milk were also more likely to be obese — but these factors were tiny in comparison with tooth brushing.meanwhile school policies, such as whether the kid was in physical education or ate school lunches, had no predictive power for whether or not a child was obese.

　　没有证据显示学校是导致肥胖增长的罪魁祸首。我们将大部分导致孩子变胖的假定原因推到学校伙食、自动售货机和体育锻炼上，因而出现了和肥胖有关的诸多抱怨。然而，我觉得这样的说法毫无根据。譬如说，在观察了一份有关中学生和大学生健康行为的调查后，我发现一个孩子是否肥胖的最佳预知方法是看刷牙。比他们吃了多少垃圾食品，喝了多少苏打饮料，进行了多少体育锻炼更为重要的是他们是否刷牙。14到17岁间每天刷牙超过一次的孩子中，仅有16%得了肥胖症，而刷牙次数每天少于一次的孩子，肥胖率为24%。当然，其他因素也很重要——玩电脑次数过多，吃过多的快餐食品，喝牛奶太少的孩子也很可能得肥胖症， 但是这些因素和刷牙比起来，微不足道。同时，学校政策，比如孩子是否接受体育锻炼，是否在学校吃午餐不能成为他是否会得肥胖症的预兆。