The influence of the cholecystokinin (CCK) antagonist L-364,718 (0.1 mg/kg) on short-term control of food intake was studied in 6 pigs. Arterial injection of L-364,718 abolished the inhibition of intake to CCK octapeptide infusion (4 μg/kg/hr; from 42% p<0.001, to 97% of control intake), but did not alter control intake (99%). Injectio of L-364,718 also abolished the inhibition of intake to duodenal infusion of emulsified fat (12 g/hr; from 76% p<0.001 to 105%) and of monoglyceride (24 g/hr; from 64% p<0.001 to 101%), but did not alter the inhibition to oleic acid (60 g/hr; 48% p<0.01 and 61% p<0.02), to glycerol (127 g/hr; 84% p<0.05 and 89%) or to glucose (144 g/hr; 78% p<0.02 and 69% p<0.001). These results suggest that monoglyceride-induced CCK secretion is mainly responsible for the satiety to duodenal fat in the pig, but that there is also a CCK-independent effect via the fatty acid. The results further indicate that intake of a normal barley-based diet (2% fat) is controlled via CCK-independent mechanisms.