In a study of more than 4,000 children, the Pardee Rand Graduate School found limiting soft drink availability at school is associated with a 4 percent decrease in overall consumption; 26 percent of children who have access to soft drinks at school drink them; and poor and black non-Hispanic children consume more soft drinks at school and more soft drinks overall.

In May 2006, an agreement was reached by the Alliance for a Healthier Generation and the American Beverage Association on voluntary sales restrictions on "competitive foods" such as soft drinks at schools.

"Greater reductions in children's consumption of soft drinks will require policy changes that go beyond food availability at school," the researchers said in a statement. "Such polices may include zoning regulations on food outlet types in residential or school areas and promotion of more healthful substitutes such as milk and fruit juice."

The findings were published in the journal of the American Dietetic Association.