Background: Cholecystokinin is associated with satiety. Fat stimulates cholecystokinin release, and fiber appears to prolong cholecystokinin elevation during the alimentary period.
Objective: We tested whether adding fiber or fat to a low-fat, low-fiber meal increases cholecystokinin release and enhances subjective measures of satiety and whether the cholecystokinin response correlates with subjective measures of satiety.
Design: Three isoenergetic breakfast meals were tested in a randomized crossover design: low fiber, low fat; high fiber, low fat; and low fiber, high fat. Blood samples were drawn from fasted subjects (7 men and 8 women) before and at different time points after test meal consumption for 6 h. Plasma was analyzed for cholecystokinin, insulin, glucose, and triacylglycerols. Visual analogue scales were used to assess subjects' hunger, desire to eat, fullness, and prospective consumption.
Results: In the women, the meals higher in fiber or in fat resulted in greater feelings of satiety and in significantly higher cholecystokinin responses than did the low-fat, low-fiber meal. In the men, the increase in cholecystokinin concentration did not differ between meals, but the 2 low-fat meals elicited a greater feeling of satiety than did the high-fat meal. The insulin response was significantly higher for the low-fiber, low-fat meal than for the other 2 meals, and the triacylglycerol response was greatest for the high-fat, low-fiber meal.
Conclusion: In women, the feeling of satiety caused by cholecystokinin release is enhanced by increasing either the fiber or fat content of a low-fat, low-fiber meal.