In the vast majority of affected individuals, obesity involves overconsumption of food relative to calorie requirements. The sensory function of the stomach may play a key role in the cessation of food ingestion. This sensation of the stomach is, in part, determined by its motor functions, such as tone and compliance and the rate of emptying. However, studies of gastric emptying in normal-weight and obese persons have shown inconsistent results. Gastric capacity was larger in obese persons when tested with an intragastric latex balloon filled with water. In contrast, other studies using the barostat or imaging (single-photon emission computed tomography) techniques reported no differences in gastric volume or compliance between obese and lean subjects. On the other hand, increased body mass and fasting gastric volume are independently associated with delayed satiation under standard laboratory conditions of food ingestion. These data suggest that changes in gastric motor and sensory functions in obesity may present useful targets to prevent and treat obesity. Further well-controlled, validated studies are needed to clarify the potential role of altering the stomach's function as a means of controlling food intake in obesity.