Scientists and nutritionists have long suspected that high-fructose corn syrup, used to sweeten soft drinks, is one of the causes of childhood obesity. In a recent study, at the

University of Cincinnati, researchers found that mice that drank water with added

fructose ate less solid food, gained more weight, and put on 90% more body fat than

mice that drank only water. Scientists concluded that fructose may affect metabolism in

a way that favors fat storage.

What is the independent variable?

The mice that drank only water

The presence of fructose in their diet

The quantity of water provided

The weight gained by the mice