Expectation and sensory cues help explain why beverage consumption could lead to weight gain

When people drink sweetened beverages they feel less satisfied than when they eat solid foods and they don’t compensate at subsequent eating occasions for the calories they got from the beverages.

This study was designed to find out why this occurs. The authors wanted to know if cognitive and sensory aspects of liquid and solid foods affected appetite, satiety, transit time, and endocrine responses that could affect calorie intake.

The 52 adults in the study underwent four tests. In one condition they drank a cherry flavored liquid that they expected to stay liquid in their stomach. In the second condition they drank the same liquid, but researchers convinced them via lab magic that the liquid would turn solid in their stomach. In the third condition, they ate a cherry-flavored gelatin cube that they expected to melt and become liquid in their stomach, and in the last condition, they ate a gelatin cube that they expected would stay solid in their stomach.

Both the liquids and solids contained the same amount of calories. All these “preloads” actually stayed or turned to a liquid in the stomach. When the participants drank the liquids or thought a preload would become a liquid in their stomach, they reported more hunger and less feeling of fullness.

Transit time through the stomach and intestines increased, and endocrine responses occurred that would explain the decreased satiety associated with liquid consumption.

On the days the participant consumed a preload that they thought would be liquid in their stomachs, they are more calories. The study findings suggest that cognitive and sensory aspects of food form affect physical and endocrine responses to the food.

This helps explain why sugar sweetened, clear beverages could lead to increased calorie intake.