Fig. 2.

Hourly (A and C) and cumulative (B and D) lymphatic glucose-dependent insulinotropic polypeptide (GIP) output following either a duodenal carbohydrate, whey protein, or saline bolus (0.275, 0.55, 1.1, 2.2, 4.4 kcal for each nutrient). Hourly output was determined by multiplying together the lymph flow rate by the hourly GIP concentration. Cumulative secretion was calculated by summing together the hourly GIP output values during the 3-h collection period. Values are means + SE. *P < 0.05 vs. saline at time of peak secretion (A). *P < 0.05 vs. saline, #P < 0.05 vs. carbohydrate 0.275 kcal, and ^P < 0.05 vs. carbohydrate 0.55 kcal (B).