Narrator: Do we have a biological trigger in our brains that let's us know when we have eaten enough? This is Science Today. Barbara Schneeman, a nutrition professor at the University of California, Davis examined this very question in a recent study and found that increasing fiber content in a person's meal raised a naturally-occurring hormone in the small intestine called Cholecystokinin, or CCK, which has been found in previous studies to signal fullness.
Schneeman: And what we found is, the more full they felt, the least hungry they felt, the higher their CCK response.
Narrator: In female subjects, adding fiber or fat to the meal enhanced that feeling of fullness and raised the amount of the CCK. Schneeman says this demonstrates a correlation between a biological signal of fullness and a person's subjective measure of fullness.
Schneeman: And I think that's going to help us with our future research, knowing that we can verify with a biological marker what's actually happening when a person eats a meal.
Narrator: For Science Today, I'm Larissa Branin.