KHK and Nephropathy: The proposed mechanism that could explain why a high fructose diet could be associated with kidney damage is the following: Fructose is transported passively in the intestines by the GLUT5 transporter [27] and then is phosphorylated by ketohexokinase in an unregulated manner, causing hepatic ATP depletion and decreased protein synthesis, with inflammatory and prooxidant changes [28–30].