问答题 The proportion of children in America who are overweight has tripled over the past 20 years and now exceeds 17% , according to the Centres for Disease Control and Prevention (CDC). The health problems that this causes include hypertension and type-2 diabetes, formerly known only among the nation's overweight adult population. A group sponsored by the National Institute on Ageing has warned that this may be the first generation ever to have a shorter lifespan than their parents.
All the while, the proportion of children who take part in daily exercise at high school has dropped from 42% in 1991 to only 28% in 2004, according to the CDC. Snacking has greatly in-creased; the Government Accountability Office found in 2003 that 99% of America's high schools now sell snacks and other food as well as providing lunches.
In an attempt to get the problem tackled at local level, Congress in 2004 passed an act directing school districts that get money from the national school-lunch programme to create "wellness" policies by the start of the 2006-07 school year. The districts were told to set standards for nutrition, physical activity and education about good food, then make sure that schools actually implement them.
One year after the deadline, the results are haphazard. School districts' plans range from a few paragraphs long to more than 25 pages. Some states, like Texas and Arkansas, have pre-emptively set standards for school districts under their jurisdiction, forcing schools to ban fizzy drinks and junk food while increasing the amount of exercise the pupils take. Others offer guidelines rather than man-dates, with no repercussions for schools that don't comply. And in some areas, schools are being eased into change very slowly. Oregon's legislature passed a bill in June that gives its schools ten years to meet its new physical-education requirements.
Last October the School Nutrition Association (SNA), a pressure group, analysed health policies from the 100 largest school districts in the country, which account for almost a quarter of the nation's primary-and-secondary-school students. Many districts had indeed created guidelines for nutrition education, physical activity and school food, as required, but the rules tended to be fairly broad. Some policies merely defaulted to the state recommendations and some to the federal government's minimal requirements. The physical-activity guidelines were also varied; only 62% of schools made physical education obligatory.
Action for Healthy Kids, another schools-oriented NGO, also looked at a smattering of policies last year. Of the 112 districts it analysed, only 30% specified a time requirement for physical-edu-cation classes and 42% offered only general guidelines for the sort of food and drink allowed to be sold in the schools. Cafeterias where nachos, French fries and cookies are tucked alongside salads, juice and fresh fruit do not encourage children to eat well.
The SNA has now done a follow-up. It found that less than half of the schools were implemen-ting their nutrition-education guidelines and enforcing vending-machine rules. The sporty bits fared better, with 64% of the schools meeting their physical-education requirements.
Bringing the issue to a local level is meant to make up for the dearth of guidelines from the fe-deral government. Other than banning chewing-gum and sweets from the cafeteria at lunchtime, there are no national guidelines for food sold outside the school lunch programme, nor are there any requirements for physical education. So far, the 2004 act does not seem to be doing enough to change that.