VENDING MACHINES have become a lucrative source of cash for many schools, dispensing soda and other high-calorie drinks that have no nutritional value to children along with millions of dollars to their schools. Meanwhile -- and perhaps it is related -- childhood obesity is on the rise, with rates doubling in the past two decades. For this reason, and also because sodas can promote cavities, the American Academy of Pediatrics has recommended that "sweetened drinks" be eliminated from schools. A growing number of jurisdictions are moving, or considering moving, to do that.

Reacting to this concern, the American Beverage Association, the industry's trade group, issued guidelines last week for member companies about soda sales in schools. The guidelines are a modest improvement, particularly in middle schools, where under the nonbinding rules soda machines would be turned off during school hours. For the most part, though, the guidelines don't change the status quo; they seem to be aimed more at fending off additional restrictions. They are, you might say, more fizz than substance.

The new guidelines would apply different rules to elementary, middle and high schools. Sales of soda and other sweetened drinks would be prohibited in elementary schools; only water and 100 percent juice would be allowed. That's great, except that is already the situation almost everywhere. The biggest and most welcome change would come, as noted above, in middle schools.

Unfortunately, that policy of no soft drinks during the school day wouldn't extend to high schools. Instead, the only restriction for high schools would be a requirement that beverage vending machines set aside half their slots for healthier beverages. That's not adequate. Moreover, under the industry's approach, sugar-filled sports drinks would be considered healthy beverages even though they are little more than soda without the bubbles. Far preferable would be to simply ban sugared sodas and similar drinks from school vending machines, at least during the school day.

Some local jurisdictions have already gone further. In the District, soda is not permitted in vending machines for students, and, beginning this school year, only 100 percent fruit juice and water will be available. In Montgomery County, vending machines can't sell sodas or drinks containing less than 50 percent fruit juice until after the end of the school day. Fairfax County has prohibited soda for years, sells only water and 100 percent fruit juice to elementary schoolers, and sells only juices with a minimum of 25 percent fruit juice to middle- and high-schoolers. The beverage industry's new guidelines are a step in the right direction, but it's time for schools to kick the soda habit once and for all.