Comparison of oral and gastric administration of sucrose and maltose on gastric emptying rate and appetite.

OBJECTIVES: To investigate mechanisms by which specific sugars affect feeding behaviour. DESIGN: In an initial study, gastric emptying rate and appetite were measured following ingestion of lemon flavoured solutions of sucrose, maltose (2160 kJ, 575 ml) and water control (67 kJ, 575 ml) given in randomised order on separate days to six male volunteers. In a second study, the effects of intragastric infusions of sucrose and maltose on appetite and gastric emptying were compared in six male volunteers. RESULTS: When given orally, both the sucrose and maltose solutions slowed gastric emptying compared with water, however sucrose emptied at a faster rate than maltose. The sucrose preload increased fullness and decreased prospective consumption during the following 3 h compared with maltose and water. When administered intragastrically, the gastric emptying rate of sucrose was again faster than that of maltose but there was no difference in ratings of hunger, fullness or prospective consumption for 3 h following the infusions. CONCLUSIONS: These results show that gastric emptying of sucrose is faster than that of maltose and suggest that gastric emptying rate and hence period of gastric distension is not the predominant factor regulating appetite by these sugars. The differences observed between oral and gastric delivery suggest that oro-sensory and cognitive factors, possibly stimulated by the sweetness of sucrose, were involved in the induction of satiety.