That's coming from a new study by researchers at the University of Illinois at Chicago.
They found kids just get their fixes somewhere else or drink more sugary fruit juices and high-calorie sports drinks instead.
The study looked at thousands of students in 40 states. It included schools that banned only sodas, schools that banned all sugary drinks and schools that allowed any drink to be sold.
Researchers found that in all three types of schools... the rate of obesity was about the same-- 22-percent.