Body weight and fasting blood glucose levels in GIPR−/− and GIPR+/+ mice. (A) Growth curve. ○, GIPR+/+; ■, GIPR−/−. Body weight was measured in g at 1, 2, 4, 8, 12, and 20 weeks. (B) Fasting plasma glucose levels were measured after a 16-hr fast. Open bars, GIPR+/+; filled bars, GIPR−/−.