American kids are fat and getting fatter. In the late 1970s, about 7 percent of U.S. children between the ages of six and 11 were considered obese, according to the federal Centers for Disease Control. The percentage now is more than 13 percent, even higher among teens and in certain demographic groups. The reasons why are no surprise. Children are simply a mirror of the country at large: 127 million American adults are overweight, almost half of them officially deemed obese. These Americans typically eat poorly and exercise infrequently, if they exercise at all. It's pretty much the same with overweight children, whose diets tend to be dominated by fatty fast foods and sugary snacks; who watch too much TV (about four hours a day on average) and who rarely venture outside to play (less than two hours a day on average). According to a Centers for Disease Control (CDC) study in 2000, roughly half of all school districts with middle and/or high schools had distribution contracts with soda vendors. Almost 80 percent of these districts negotiated to get a specified share of receipts. In these districts, students typically can buy sodas from vending machines, snack bars, school stores, even the cafeteria. That soda helps wash down a multitude of junk food: 70 percent of the schools surveyed by the CDC permitted the sale of low-nutrition snacks during lunch. At the other end of the spectrum, fewer than 10 percent of the districts surveyed provided daily physical education classes or the equivalent--this despite the fact the CDC and other health authorities recommend children and teens participate in moderate to vigorous physical activity for one hour five times a week. Not surprisingly, school officials find themselves in a tight spot. Most say they would like to do more, but there are other considerations.