A 2-pyridone compound represented by the formula [1]: {wherein in the formula [1], the ring represented by A represents a benzene ring or a pyridine ring, X represents any of the structures represented by the formulas [3] shown below: V represents a single bond or a lower alkylene group, and W represents a single bond, an ether bond or a lower alkylene group (wherein the lower alkylene group may contain an ether bond)}, a tautomer or stereoisomer of the compound, a pharmaceutically acceptable salt thereof, or a solvate thereof is a compound that has an excellent GK activating effect and is useful as a pharmaceutical.